Question

8. AABC is an isosceles triangle such that AB = AC, AD I BC.
a) Prove that angle ABD angle ACD.
b) Prove that angle B - angle C?
c) Is D the mid-point of BC?
BD

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Answer 1

Step-by-step explanation:

a) in triangle ABD and triangle ACD

AB=AC(given)

ADB=ADC(given)

AD=AD(Common side)

thus by Sas Congrence criteria

Triangle ACD~=ABD

AND=ACD(Cpct)

Answer 2

Step-by-step explanation:

ABC is an isoscles triangle

ab=ac (common)

ad ! bc

(1) angle ABD=ACD

angle ABD=1/2 ABC

angle ACD=1/2 ABC

AD=AD. (common)

so angle ABD=ACD

(2) angleB=ANGLE C

BD=DC

angle B=C

(3) D is the mid point of BC

angle DAB=angle DAC

AD=AD

So... D is the mid point of BC