It is proved that the bisectors of the two base angles of an isosceles triangle are equal.

Proposition: triangle ABC is an isosceles triangle, and BD and CE are bisectors of angle B and angle C respectively.

Prove that BD=CE

Proof: Because the triangle ABC is an isosceles triangle.

So AB=AC

Angle B= angle c

Because BD bisects angle B.

Bisecting angle c

So angle ABD= angle ACE

In triangle ABD and triangle ACE

Jiao Yigong * * *

AB=AC

Angle ABD= angle ACE

So triangle ABD is equal to triangle ACE.

So BD=CE