Question 666732
x^2+x^2=40^2  x= leg(both x because they are the same)
2x^2=40^2     combined like terms
2x^2=1600     Simplify (40^2= 1600)
x^2=800       Divide Both sides by 2
x=sqrt 800    sqrt of both sides( its long on the calc.)

Hit show source it's easier to read.