Question

prove that angle opposites two equal side of a isocelus tringle are equal​

Answer 1

given= ABC is an isosceles triangle with AB=AC

to prove= angle B=angle C

const= draw the bisectore of angle A & let D be the point of intersection of the bisector of angle A and BC

proof=

in triangle ABD and triangle ACD

AB=AC (given)

angle BAD=angle CAD ( AD is bisector of angle A)

AD=AD (common side)

by SAS congruence rule

triangle ABD congruent to triangle ACD

so angle B = angle C( by cpct)

hence proved