#1**+1 **

Connect WY....this will form right triangle WXY

Since WX = WY....then this will be an isisceles right triangle

And WY = √[4^2 + 4^2] = √32

And angle WYX = 45

So....in triangle WYZ, angle WYZ = 135 - 45 = 90

So.....triangle WYZ is also a right triangle with WZ being the hypotenuse

So....

a = √(WZ^2 - WY^2) = √ ( 9^2 - (√32)^2 ] = √ [81 - 32] = √49 = 7

CPhill Apr 13, 2019