In equilateral $△
PXY,themeasureof∠
PXYis60°andPX=XY$.
In square WXYZ, the measure of
∠WXY is 90° and WX=XY.
Therefore, $∠WXP=∠WXY−∠PXY=90°−60°=30°andWX=PX$.
Thus △WXP is isosceles,
and so $∠PWX=∠WPX=2180°−30°=75°$.
The measure of ∠PWZ is $90°−∠PWX=90°−75°=15°$.
In a similar way, we can show that $∠PZW=15°,andso∠WPZ=180°−∠PWZ−∠ PZWor∠WPZ=180°−15°−15°=150°$.