Measurement and reproduction of an angle (3 exercices)
Introduction to alternate/internal and corresponding angles (2 exercices)
Definition and alternate/internal and corresponding angles (3 exercices)
Measurement and alternate/internal and corresponding angles (4 exercices)
Alternate/internal and corresponding angles: reciprocal properties (5 exercices)
Sum of the angles in a triangle (10 exercices)
Sum of angles and particular triangles (9 exercices)
Deductive reasoning (4 exercices)
Us-math (2 exercices)
a1a2a3a4b1b2b3b4ABCDEFGABCDEFGHIJKLMNOPQRST3.Definition
andalternate/internalandcorrespondinganglesE.1406Definition:In
aconfigurationoftwolinesandathirdlineintersectingthefirsttwo:twoanglesaresaidtobealternate
interioranglesif
theysatisfythefollowingthreeproperties:theirverticesarethepointsofintersectionofthesecantlinewiththetwolines,theyarelocatedoneithersideofthesecantline,theyarelocatedbetweenthetwolines.Twoanglesaresaidtobecorrespondingif
theysat-isfythefollowingthreeproperties:Theirverticesarethepointsofintersectionofthesecantwiththetwolines.theyarelocatedonthesamesideofthesecant,oneislocatedbetweenthetwolines,theotherout-side.Below,weconsidertheconfigurationconsistingofthreelines:Complete,if
possible,
thefollowingtable:ABAnglesAandBare:a1a3a4b3a2b3a1b1a3alternate
interioranglesb4oppositethevertexE.1388
Inthefigurebelow,AECDis
atrapezoid.Wecall:thepointBthe
intersectionofline(AE)with
thelinepassingthroughpointCand
paralleltoline(AD).
thepointFintersectionoftheline(AE)with
thelinepassingthroughthepointDand
paralleltotheline(CE).
pointGintersectionoflines(DF)and(CB).
1Reproducetheabovefigurefreehand.2Lines(AE)and(DC)define
pairsofcorrespondingan-glesofequalmeasure.Coloroneofthesepairsandlabelthem.3Lines(AD)and(CG)define
pairsofalternateinterioranglesofequalmeasure.Coloroneofthesepairsandnamethem.4Inthefigure,colorapairofanglesoppositeatthevertexinredandnamethem.E.10863Considerthetilingoftheplanebelow:1GivetwoalternateinteriorangleswithrespectiveverticesIandS.
2GivetwocorrespondingangleswithrespectiveverticesGandN.4.Measurementandalternate/internalandcorrespondinganglesE.1396Proposition:In
aconfigurationoftwolinesandathirdintersectingline.SiThe
twolinesareparallel.ThenThe
pairsofalternateinterioranglesareequalinmeasure,andthepairsofcorre-spondinganglesareequalinmeasure.https://chingmath.frchapExoCorrec/1406sacados/1406a1a2a3a4b1b2b3b4chapExoCorrec/1388sacados/1388ABCDEFGchapExoCorrec/10863sacados/10863ABCDEFGHIJKLMNOPQRSTchapExoCorrec/1396sacados/1396ABxyvust62oABCDEFGH(d(d62oABCDwzsvtyxu155o25oABCDxxyyzztt22o116oABxyvust55o55oABxyvust109o109oIn
thefigureopposite,lines(xy)and(uv)are
parallel:1ListallanglesequaltoanglexAt.
2GivethemeasureofanglevBs.
Justifyyouranswer.E.6671Considerthefigurebelow:1aNameapairofcorrespondingangles.bNameapairofalternateinteriorangles.2WhatpropertyismissingfromthisfigureforangleCAEto
measure118o?E.10866
Considerthefourstraightlines(ux),(ty),(sv),(wz)shownbelow:Inaddition,wehavetheinformation:vBx=
155o;wDt=
25o;(ux)==(ty);(sv)==(zw)1
GivethemeasureoftheanglewCx.
Justifyyourresult.2GivethemeasureoftheanglezCx.
Justifyyourresult.E.11478Considerthefigurebelowwhere:(xx)==(yy);(zz)==(tt)1
JustifythatangleDBAmeasures22o.
2JustifythatangleABtmeasures116o.
3DeducethemeasureofangleDBC.5.Alternate/internalandcorrespondingangles:reciprocalpropertiesE.10801Proposition:Consider
twolinesintersectedbyasecant.SiTwoalternateinterioranglesinthisconfigurationhavethesamemeasure.Therefore,these
twolinesareparallel.Considertheconfigurationbelow:Justifythatlines(xy)and(uv)are
parallel.E.10803Proposition:Consider
twolinesintersectedbyasecant.SiTwocorrespondinganglesinthisconfigurationhavethesamemeasure.Therefore,these
twolinesareparallel.Considertheconfigurationbelow:Justifythatlines(xy)and(uv)are
parallel.https://chingmath.frABxyvust62ochapExoCorrec/6671sacados/6671ABCDEFGH(d(d62ochapExoCorrec/10866sacados/10866ABCDwzsvtyxu155o25ochapExoCorrec/11478sacados/11478ABCDxxyyzztt22o116ochapExoCorrec/10801sacados/10801ABxyvust55o55ochapExoCorrec/10803sacados/10803ABxyvust109o109oxxyyttMN143o37oABCDEFGHIJK75o105o(AB==(CDABCD(AB==(CDABC37o46oDEF43o62o72o86;5o33o122oABCDABCDEE.11506
Considertheconfigurationbelow,drawnfreehand:Wehavethefollowinginformation:xMt=143o;yNt=37o1
Justifythat:tNy=
143o2
Whatcanbesaidaboutlines(xx)and(yy)?
Justifyyouranswer.E.10864Belowhasbeenreproduced,free-hand,afigureincludingthethreestraightlines[AB],[CD],[EF]cut
bythesecant[GH]with
forinformation:BIG=
75o;JKE=
105o;(AB)==(CD)1
GivethemeasureoftheangleIJD.
Justifyyourreason-ing.2aGivethemeasureoftheangleDJK.
Justifyyourreasoning.bJustifythatthestraightlines(CD)and(EF)are
par-allel.Indication
:eachanswermustbejustified.E.10861
BelowisatrapezoidABCDand
itsdiagonals:1GivetwoalternateinterioranglesofequalmeasurewithrespectiveverticesDandB.
2GivetwoalternateinterioranglesofdifferentmeasureswithrespectiveverticesAandC.6.Sum
oftheanglesinatriangleE.1394
ConsiderthetwotrianglesABCandDEFshownbelow:1Determinethemeasureoftheangle∠ACB.
Justifyyourapproach.2Determinethemeasureoftheangle∠DFE.
Justifyyourapproach.E.1407DeterminethemeasureoftheangleCBD.
Justifyyourapproach.E.1387
1Drawafiguresimilartothefigureoppositewhoseangleshavethefollowingvalue:AEB=
65o;ACB=
30oBDE=
60o2
Provethatthestraightlines(AC)and(DE)are
perpendic-ular.E.1391Ineachcase,saywhetheritispos-sibletoconstructthefollowingtriangles:aAB=
6cm;BC=
5cm;AC=
12cmbABC=
32o;BAC=
98.5o;ACB=
49.5ocZC=
3cm;CT=
3cm;TZ=
6cmdXYZ=
36o;Y
XZ=
47o;XZY=
98oeAB=
5cm;CAB=
50o;ABC=
130ohttps://chingmath.frchapExoCorrec/11506sacados/11506xxyyttMN143o37ochapExoCorrec/10864sacados/10864ABCDEFGHIJK75o105o(AB==(CDchapExoCorrec/10861sacados/10861ABCD(AB==(CDchapExoCorrec/1394sacados/1394ABC37o46oDEF43o62ochapExoCorrec/1407sacados/140772o86;5o33o122oABCDchapExoCorrec/1387sacados/1387ABCDEchapExoCorrec/1391sacados/1391ABCDO103o76o22oABCD32o83o34o41oABCDABCEF83o66oABCDEF46o43oABCDI27oMN34o(AB==(CDE.11507
ConsiderthequadrilateralABCDdrawnfreehand.LetObethepointofintersectionofthediagonals:Wehavethefollowinginformation:DOC=
103o;DAC=
76o;ABD=
22o1
GivethemeasureofangleAOB.
2IntriangleABO,
determinethemeasureofangleOAB.
Justifyyourapproach.3aJustifythatanglesDAOandOABare
adjacent.bGivethemeasureofangleDAB.
E.1400Inthefigureopposite,ABCis
anytriangleandthepointDbelongstothesegment[AC]1
CalculatethemeasureoftheangleBDA.
2DeducethemeasureoftheangleBADIt
isassumedforthenextquestionthatthetriangleABCisisosceles
inA:
3DeducethemeasureoftheangleACBE.6672
TheconfigurationbelowconsistsofarighttriangleABCatCsuchthatpointsD,B,
andAare
aligned.DeterminethemeasureofangleDCB.The
wordingofyouranswersandthepresenceofthestepsinyourreasoningwillbetakenintoaccountintheevaluation.E.1404
ConsiderthetriangleABCshownbelow,withpointsEandFsuchthat(AB)==(EF).1
DeterminethemeasureofangleCBA.
Justifyyouran-swer.2aDeterminethemeasureofangleCEF.
Justifyyouranswer.bDeducethemeasureofangleCFE.
Justifyyouran-swer.E.1399Considerthefigurebelow,consistingof:thetriangleABC,
whichisarectangleatC,
suchthat:BAC=46othe
pointsEandF,
lyingon[AB]and[BC]respectively,suchthat:(BC)⊥(EF)pointD,
whichlieson[AC],
satisfiesthefollowingcon-dition:AED=43o1
Whatcanbesaidaboutlines(CD)and(FE)?
2FindthemeasureofangleBEF.
3WhattypeofquadrilateralisCDEF?
E.10865Considerthefigurebelowcomposedofthefourstraightlines(AB),(CD),(AD),(BC)below:Wehavetheadditionaldata:MCN=
34o;IAB=
27o;(AB)==(CD)Determine
themeasureoftheangleCID.Hint:this
questionshouldbedealtwithinseveralsteps.Eachstepshouldbejustified.7.Sum
ofanglesandparticulartriangleshttps://chingmath.frchapExoCorrec/11507sacados/11507ABCDO103o76o22ochapExoCorrec/1400sacados/1400ABCD32o83ochapExoCorrec/6672sacados/667234o41oABCDchapExoCorrec/1404sacados/1404ABCEF83o66ochapExoCorrec/1399sacados/1399ABCDEF46o43ochapExoCorrec/10865sacados/10865ABCDI27oMN34o(AB==(CDABCa25oABCb72oABCc36oABCDEF70oABCD60oABC75o120oDABCDMNC47oE.1398
Determine,ifpossibleforeachques-tion,themeasureoftheangleABCE.1402
EachlinerepresentsadifferentisoscelestriangleABC.
Usingthemarkedinformation,findthe(s)information(s)that
ismissing(s):Main
vertexABCA30oB30oC45o35o110o35o50o50o80oE.11479
EachlinerepresentsadifferentisoscelestriangleABC.
Usingthemarkedinformation,findthe(s)information(s)that
ismissing(s):Main
vertexABCaA35obB70oc120oE.1395
Considerthetwotrianglesshownbelow:1aWhatisthenatureofthetriangleABC?
bWhatisthemeasureoftheangle∠ABC?
2aWhatisthenatureofthetriangleDEF?
bWhatisthemeasureoftheangle∠EDF?E.1408
Considerthefigurebelow:1aShowthatthetriangleDCBis
anequilateraltrian-gle.Justifyyourapproach.bWhatisthenatureofthetriangleABD?
2WhatisthemeasureoftheangleABD?
Justifyyourapproach?3DeducethevalueoftheangleDAB.
Justifyyourap-proach.E.6673ConsidertheconfigurationbelowwheretriangleABCisisosceleatA.
PointDbelongstosegment[AB].
DeterminethemeasureofangleDCB.The
wordingofyouranswersandthepresenceofthestepsinyourreasoningwillbetakenintoaccountintheevaluation.E.1389ABCDis
arectangle.PointsMandNare
thepointsofintersectionofcircleCwith
segments[BC]and[AD],
respectively.1WhatisthenatureoftriangleAMN?
2WhatisthevalueofangleMAN?
3CalculatethevalueofangleANM.
4WhatisthevalueofangleCMN?
Justifyyourapproach.https://chingmath.frchapExoCorrec/1398sacados/1398ABCa25oABCb72oABCc36ochapExoCorrec/1402sacados/1402chapExoCorrec/11479sacados/11479chapExoCorrec/1395sacados/1395ABCDEF70ochapExoCorrec/1408sacados/1408ABCD60ochapExoCorrec/6673sacados/6673ABC75o120oDchapExoCorrec/1389sacados/1389ABCDMNC47o4cmABCD40o25o???????????EABCDxy(d)(d)(d)//(d)ABICCJesaisJ’uti-liseJ’endéduisIest le milieu du segmentABBest l’image deApar la symétrie de centreIJesaisJ’uti-liseJ’endéduisSideuxdemi-droitessontparallèlesetd’orientation opposéalorsellessontsymétriquesde centre de symétrie le milieu des originesLa demi-droiteAxa pour imageBypar rap-port àIJesaisJ’uti-liseJ’endéduisCAx,l’imagedeAxparrapportàIestByet celle deCestCL’appartenance est conservée par la symétrie cen-traleC:::JesaisJ’uti-liseJ’endéduisL’angleIACapourimagel’angleIBCparlasymétrie de centreIE.10691
ConsiderthetriangleABCbelowandthepointMbelongingtothesegment[AC].
WhatisthenatureofthetriangleBCD?
Justifyyourasser-tion.
E.5755ConsiderasquareABCDin-sidewhichanequilateraltrian-gleABEis
drawn.Arepre-sentationofthisconfigurationisshownopposite.Determinethemeasureoftheanglesrepresentedbythesym-bolˇ?ıandjustifyeachofyourresults.8.DeductivereasoningE.1401
Thefigurebelowconsistsofthestraightlines(d)and(d)parallel
toeachother.Thestraightline(Δ)interceptingthestraightlines(d)and(d)AandBrespectively.WenoteIthe
middleofsegment[AB].
Inthisexercise,wewanttoshowthatthealternating-internalanglesIAxandIByare
equal.Todothis,weplaceapointCon
thehalf-line[Ax),
traceCits
symmetricalwithrespecttoI.
TheaimistoshowthatthepointCis
apointonthehalf-line[By):
thus,thehalf-right[AC)will
haveasitsimage[BC],
makingitpossibletoaffirmthattheanglesCAIandCBIare
symmetricalandtheywillbeofthesamemeasurement.Completethetablebelowrepresentingthedeductivelinkinthedemonstration:https://chingmath.frchapExoCorrec/10691sacados/106914cmABCD40o25ochapExoCorrec/5755sacados/5755???????????EABCDchapExoCorrec/1401sacados/1401xy(d)(d)(d)//(d)ABICCJesaisJ’uti-liseJ’endéduisIest le milieu du segmentABBest l’image deApar la symétrie de centreIJesaisJ’uti-liseJ’endéduisSideuxdemi-droitessontparallèlesetd’orientation opposéalorsellessontsymétriquesde centre de symétrie le milieu des originesLa demi-droiteAxa pour imageBypar rap-port àIJesaisJ’uti-liseJ’endéduisCAx,l’imagedeAxparrapportàIestByet celle deCestCL’appartenance est conservée par la symétrie cen-traleC:::JesaisJ’uti-liseJ’endéduisL’angleIACapourimagel’angleIBCparlasymétrie de centreIABCD72;5oJesaisJ’uti-liseJ’endéduisSi un triangle est isocèle alors la mesure des deuxangles de la base principale sont égalesBCAJesaisJ’uti-liseJ’endéduisLespointsB,CetDsontalignésetformentl’angle platBCDDeux angles adjacents formant un angle plat sontsupplémentairesACDJesaisJ’uti-liseJ’endéduisLe triangleABDest isocèle enDSi un triangle est isocèle alors les deux angles dela base principale sont de mesures égales.JesaisJ’uti-liseJ’endéduisDansletriangleABD,onaABD72;5oetBAD72;5oBDAJesaisJ’uti-liseJ’endéduisACD107;5oetCDA35oCADABCD32o83oJesaisJ’uti-liseJ’endéduisTrois points alignés forment un angle platLes anglesADBetBDCsont adjacents et sup-plémentairesJesaisJ’uti-liseJ’endéduisDeux angles sont dits supplémentaires si la sommede leur mesure vaut180oBDAJesaisJ’uti-liseJ’endéduisDans le triangleBDA, on aB32oetD97oBADJesaisJ’uti-liseJ’endéduisDans un triangle isocèle, les angles de la base prin-cipale ont même mesureE.2064
ThefigurebelowshowsthetriangleABDisosceles
atDand
apointCof
thesegment[BD]suchthatABCis
isoscelesatA.
TheaimoftheexerciseistodeterminethemeasureoftheangleBAC.
Inyournotebook,copythemissingsentencesinthedeductivelinksbelow:E.2054
Considertheconfigurationshownopposite.Correctlycompleteeachofthede-ductivelinksbelowinordertoanswereachofthequestionscor-rectly:1CalculatethemeasureoftheangleBDA.
2DeducethemeasureoftheangleBADIt
isassumedforthenextquestionthatthetriangleABCisisosceles
inA:
3DeducethemeasureoftheangleACBhttps://chingmath.frchapExoCorrec/2064sacados/2064ABCD72;5oJesaisJ’uti-liseJ’endéduisSi un triangle est isocèle alors la mesure des deuxangles de la base principale sont égalesBCAJesaisJ’uti-liseJ’endéduisLespointsB,CetDsontalignésetformentl’angle platBCDDeux angles adjacents formant un angle plat sontsupplémentairesACDJesaisJ’uti-liseJ’endéduisLe triangleABDest isocèle enDSi un triangle est isocèle alors les deux angles dela base principale sont de mesures égales.JesaisJ’uti-liseJ’endéduisDansletriangleABD,onaABD72;5oetBAD72;5oBDAJesaisJ’uti-liseJ’endéduisACD107;5oetCDA35oCADchapExoCorrec/2054sacados/2054ABCD32o83oJesaisJ’uti-liseJ’endéduisTrois points alignés forment un angle platLes anglesADBetBDCsont adjacents et sup-plémentairesJesaisJ’uti-liseJ’endéduisDeux angles sont dits supplémentaires si la sommede leur mesure vaut180oBDAJesaisJ’uti-liseJ’endéduisDans le triangleBDA, on aB32oetD97oBADJesaisJ’uti-liseJ’endéduisDans un triangle isocèle, les angles de la base prin-cipale ont même mesureABCDMNC47oJesaisJ’uti-liseJ’endéduisLes pointsMetNsont deux points du cercleOn en déduit:AMANJesaisJ’uti-liseJ’endéduisAMetANsontdeuxsegmentsdemêmelongueurLe triangleAMNest isocèle enA.JesaisJ’uti-liseJ’endéduisLe triangleAMNest isocèle de sommet principalAAMNANMJesaisJ’uti-liseJ’endéduisSi un quadrilatère est un rectangle alors ses anglessont des angles droitsOn en déduit:BADABC90oOADBEFCABCDEFGHE.1390
LetABCDbearectangleandCa
circlewithcenterAintersectingsegments[BC]and[AD]atMandN,
respectively.1Copythemissingphrasefromeachdeductivechainintoyournotebook:2
aCompletethefollowingdeductivechain:bGivethemeasureofangleBMA.
3WewanttodeterminethevalueofangleCMN:
aDeterminethemeasureofangleMAN.
bDeducethemeasureofangleAMN.
cGivethemeasureofangleNMC.9.Us-mathE.9628American
notation:losrque
deuxanglessontˇde
mesureségalesı,
auxEtats-Unis,onditquelesanglessontcongru-ents.Forexample,belowthetwoangles∠BOAand∠EODare
ofthesamemeasure,wenote:∠AOB∼=∠DOFComplete
thefollowingblanks:a∠BOC∼=∠:
::;
b∠AOB∼=∠:
::cm∠COD+m∠DOE+m∠DOE=:
::E.9629
Weconsidertheconfigurationbe-low:where:←→DEand←→CFinterceptsinA;←→GHand←→CFinterceptsinB;←→DE
←→GHComplete
theblanks:1∠CAD∼=∠:
::∼=∠:
::∼=∠:
::2∠ABH∼=∠:
::∼=∠:
::∼=∠:
::10.Unclassifiedexerciseshttps://chingmath.frchapExoCorrec/1390sacados/1390ABCDMNC47oJesaisJ’uti-liseJ’endéduisLes pointsMetNsont deux points du cercleOn en déduit:AMANJesaisJ’uti-liseJ’endéduisAMetANsontdeuxsegmentsdemêmelongueurLe triangleAMNest isocèle enA.JesaisJ’uti-liseJ’endéduisLe triangleAMNest isocèle de sommet principalAAMNANMJesaisJ’uti-liseJ’endéduisSi un quadrilatère est un rectangle alors ses anglessont des angles droitsOn en déduit:BADABC90ochapExoCorrec/9628sacados/9628OADBEFCchapExoCorrec/9629sacados/9629ABCDEFGHABCDEF46o43oABCDMNC47o66o83oABCEFE.1745
Considerthefigurebelowcomposedof6points:1Herearethepropertiestouseinthisquestion:Iftwostraightlinesareparalleltothesamestraightline,thenthey
areparalleltoeachotherIftwostraightlinesareperpendiculartothesamestraightline,thenthey
areparallelIftwostraightlinesareparalleltoeachotherandsia
thirdstraightlineisperpendiculartoone,thenit
isperpendiculartoautreIfa
quadrilateralhasfourrightanglesthenthis
quadrilateralisarectangle.a
Howdoyoujustifythatthestraightlines(CD)and(FE)are
parallel?bJustifythattheangleDEFis
arightangle.cWhatisthenatureofthequadrilateralCDEF?
2aAretheanglesDAEandAEDcomplementary?bAretheanglesADEandEDCsupplementary?cArethepointsA,DandCaligned?E.1461
LetABCDbearectangleandCa
circleofcenterAinterceptingsegments[BC]and[AD]atMandNrespectively.1Copythemissingsentencefromeachdeductivelinkontoyournotebook:a.....................................................IfaquadrilateralisarectangleThenitsanglesarerightangles.Wededuce:BAD=ABC=90o.
bThepointsMandNare
twopointsonthecircleCwith
centerA.
.....................................................Wededuce:AM=AN.
c[AM]and[AN]are
twosegmentsofequallength.....................................................ThetriangleAMNis
isoscelesatA.
dtriangleAMNis
isosceleswithprincipalvertexA.
.....................................................Wededuce:AMN=ANM.
Answerthefollowingquestions,justifyingeachofyourstate-ments:2GivethemeasureoftheangleBMA.
3WewishtodeterminethevalueoftheangleCMN:
aDeterminethemeasureoftheangleMAN.
bDeducethemeasureoftheangleAMN.
cGivethemeasureoftheangleNMC.
E.1743ConsiderthetriangleABCoppo-sitesuchthat(AB)==(EF).
Answerthequestionsbelowbywritingyourreasoningintheformofdeductivechains:1CalculatethemeasureoftheangleFBA.
2aDeterminethemeasureoftheangleCEF.
aDeterminethemeasureoftheangleCFE.https://chingmath.frchapExoCorrec/1745sacados/1745ABCDEF46o43ochapExoCorrec/1461sacados/1461ABCDMNC47ochapExoCorrec/1743sacados/174366o83oABCEFABCD60oABCD32o83oABCDIABC(dE.1744
ThefigurebelowshowsatriangleACDand
apointBbelongingtothesegment[AC].
Allreasoningmustbejustifiedintheformofthedeductivelink.1aShowthatthetriangleDCBis
anequilateraltrian-gle.Justifyyourapproach.(severaldeductivelinksarerequired).
bWhatisthenatureofthetriangleABD?
2WhatisthemeasureoftheangleABD?
Justifyyourapproach.3DeducethevalueoftheangleDAB.
Justifyyourap-proach.(severaldeductivechainsarerequired).
E.1746LetABCbeatriangleandDa
pointonthesegment[AC].
Somemeasurementsareshowninthefigurebelow:1DeterminethemeasureofangleBDA.
2DeducethemeasureofangleBAD.3
NowsupposethattriangleABCis
isoscelesatA.
DeterminethemeasureofangleACB.
E.2931Intheplane,consideraparallelogramABCD;
thepointIis
thepointofintersectionofthetwobisectorsDABandABC:
JustifythatthetriangleABIis
right-angledatI.
E.6448LetA,BandCbethreenon-alignedpointsoftheplaneand(d)the
bisectoroftheangleABC.
1PlaceapointMon
theline(d).
2aDrawtheline(Δ)passing
throughthepointMand
perpendiculartotheline(BA).
bNameIthe
pointofintersectionofthestraightlines(d)and(BA).
3aDrawtheline(Δ)passing
throughthepointNand
perpendiculartotheline(BC).
bNameJthe
pointofintersectionofthelines(d)and(BC).
4DemonstratethatthedistancesIMandJMare
equal.https://chingmath.frchapExoCorrec/1744sacados/1744ABCD60ochapExoCorrec/1746sacados/1746ABCD32o83ochapExoCorrec/2931sacados/2931ABCDIchapExoCorrec/6448sacados/6448ABC(d