Question 34
Let $ABC$ be an isosceles triangle, ($AB = AC$). Let $D$ and $E$ be two points on the side $BC$ such that $D \in BE$, $E \in DC$ and $2\angle DAE = \angle BAC$. Prove that we can construct a triangle $XYZ$ such that $XY = BD$, $YZ = DE$ and $ZX = EC$. Find $\angle BAC + \angle YXZ$.