A right square pyramid with volume 54 has a base with side length 6 . The five vertices of the pyramid all lie on a sphere with radius \frac{m}{n}, where m and n are relatively prime positive integers. Find m+n.
A right square pyramid with volume 54 has a base with side length 6 . The five vertices of the pyramid all lie on a sphere with radius \frac{m}{n}, where m and n are relatively prime positive integers. Find m+n.