好急!!問4條F.2 MATHS題 20分!!!

先講第6題
ANS:
ΔACD ≅ ΔBEC
angle C = angle C (common)
CD=CE(given)
angle D=angle E= 90度
so...
ΔACD ≅ ΔBEC(ASA)
so...AD=BE( corr.sides≅ Δ)
講第9題part b,c
ANS
partb
ΔBZX ≅ ΔCZY
angle Z= angle Z(vert.opp angle)
CY=BX(proved in a)
angle Y=angle X(proved in a)
so...
ΔBZX ≅ ΔCZY(AAS)
partc
BC=BX
so...
ΔBCZ is isos. tri.