Question 435512
Let s=one side of the square.
4s=P(square)
2s+sqrt(2)s=P(triangle) [sqrt(2)s is the hypotenuse]
4s-3=2s+sqrt(2)s
2s-3=sqrt(2)s
4s^2-12s+9=2s^2
2s^2-12s+9=0
s=(6+3sqrt(2))/2
4s=2(6+3sqrt(2))
=12+6sqrt(2)
.
Ed