ABC is a triangle in which ∠B=2∠C.D is a point on BC such that AD bisects ∠BAC and AB=CD. Prove that ∠BAC=72∘.

ABC is a triangle in which ∠B=2∠C.D is a point on BC such that AD

1.	ABC is a triangle in which ∠B=2∠C.D is a point on BC such that AD bisects ∠BAC and AB=CD. Prove that ∠BAC=72∘.
Answer» ABC is a triangle in which $∠ B = 2 ∠ C . D$ is a point on BC such that AD bisects $∠ B A C a n d A B = C D . Prove that ∠ B A C = 72^{\circ} .$