If a triangle with these sides is a right triangle, it will be satisfied by the Pythagorean Theorem, which states a^2+b^2 (the two shorter sides) is equal to c^2 (the longest side, called the hypotenuse). Therefore to solve this problem, we need to do:
20^2+48^2=52^2
which is
400+2304=2704
2704=2704
Since this is true, this triangle is a right triangle.
:)
