2XR=XZ
2XR=42
XR=21
a and b are the shorter sides, c is the longer side
Pythagorean theorem:a^2+b^2=c^2
In this case
(XR)^2+(WR)^2)=WX^2
((XR)^2+(WR)^2))^1/2=WX
((21)^2+(21)^2)^1/2=WX
(2(21)^2)^1/2=WX
2^1/2 x 21=WX
WX is 21 times the square root of 2