Question 282030
First find the diagonal in the 3-4 plane, we'll call that G.
{{{G^2=3^2+4^2=9+16=25}}}
That diagonal (G) now becomes a leg along with the 5 inch leg.
Now find the diagonal, H, using the two legs, G and 5.
{{{H^2=G^2+5^2=25+25=50}}}
{{{H=sqrt(50)=5*sqrt(2)}}}