Ok this is a fun little question.
So You are dealing with three sides of a right triangle. that means we can use Pythagorean's thm to solve for R
We know that [tex]A^2 + B^2 = C^2[/tex]
r=A
36=B
r+12=C
[tex]r^2 + 36^2 = (r+12)^2 [/tex]
Next simplify, [tex]r^2 + 1296 = r^2 + 24r + 144
1296-144 = 24r
1152=24r
48=r[/tex]
