Question

In an isosceles triangle $A B C$
with $A B=A C ,$
a circle passing through $B$
and $C$
intersects the sides $A Ba n dA C$
at$Da n dE$
respectively. Prove that $D E C Bdot$

Answer 1

To prove$=/_ADE=/_ABC$

Proof

$/_ABC$ is an isosceles

$/_ACB=/_ABC-(1)$

BCDE is a cyclic quadrilateral

$/_ADE=/_ACB-(2)$

From equation 1 and 2

$/_ABC=/_ADE$.