I need help pls

Draw a line from W to Y    this will be the hypotenuse of a rt triangle length = sqrt (4^2 + 4^2) = sqrt 32

   this line also makes YWZ a right riangle with hypot 9   and one leg WY = sqrt32   ....find other leg

 

9^2 = (sqrt32)^2 + a^2

81-32 = a^2 =  49                      a = 7