Question

If angle YWZ = 17, what is angle WXY?

Answer 1

We know that

step 1
if ∡YWZ=17°
then
∡XWZ=17°*2-----> 34°----> because triangle XWY and triangle YWZ are congruents

step 2
∡WXY=∡WZY-------> because triangle XWY and triangle YWZ are congruents
we know that 
the sum of the internal angles of a triangle is 180 degrees
so
180°=∡XWZ+2*∡WXY---------> ∡WXY=[180-∡XWZ]/2
∡WXY=[180-34°]/2-------> ∡WXY=73°

the answer is
∡WXY=73°