Find x using the pythagorean theorem

X= 9.33

Because side x had two intersecting lines that create 90° angles, we can assume that if we cut off the rectangular part of the shape, the other lines would be the same. Now, we are left with the triangular shape. We know that the hypotenuse is 16, but because we got rid of the rectangular part of the shape that had 5 on that side, we have to subtract 18 by 5 to make sure the shape is correct. Now, that side is 13.

Now we solve: 13^2 +x^2=16^2.
169+x^2=256
-169 -169
———————-
X^2=87

Now you square root both sides by 2, getting X= 9.33