Question

triangle ABC is an isosceles triangle in which AB=AC. show that angle B=angle C

Answer 1

Since AB = AC,

angle B = angle C as angles opposite to equal sides are equal

Answer 2

draw a bisector of angle A to BC name as AD.
now in triangle ABD and ADC
AB=AC (given)
angle BAD=angle CAD (AD bisects angle A)
AD=AD (common )
by sas congruent rule
triangles ABD=ADC
therefore, by c.p.c.t angle B=angle C