Question 938083
{{{drawing(100,100,-2.5,2.5,-2.5,2.5, 
green(line(-2,-1,2,1)), 
line(-2,1,-2,-1), line(-2,-1,2,-1), line(2,-1,2,1), line(2,1,-2,1) )}}} 
L = 8cm, w = 4cm
Pythagorean Theorem
*[illustration Pythagorean_theorem_3.jpg].
diagonal = {{{sqrt((8cm)^2 + (4cm)^2) = sqrt(80)=sqrt(16*5) = 4sqrt(5)cm}}}