%!

36 dup scale
1 36 div setlinewidth

4 6 translate 

/a 3 def
/b 4 def
% set c = sqrt(a^2+b^2)
/c 
  a a mul b b mul add sqrt 
def

newpath
0 0 moveto
0 c -1 mul lineto
c c -1 mul lineto
c 0 lineto
closepath
gsave
0 0 1 setrgbcolor
fill
grestore
stroke

b a atan rotate

newpath
0 0 moveto
a 0 lineto
a a lineto
0 a lineto
closepath
stroke

b a atan -1 mul rotate

c 0 translate

b a atan rotate

newpath
0 0 moveto
b 0 lineto
b b lineto
0 b lineto
closepath
stroke