90-x because a complementary angle is =90 degrees.
3.14?
or do you want more digits?
3.141592653589793238462643383279502884197169399375105820974944592307816406286<span> </span>
Perimeter P=2L+2W
P=24
L=w+4
P=2(w+4)+2w
24=2w+8+2w
24=8+4w
16=4w
w=4
L=8