Purple Comet 2018 HS problem 30
Source:
March 19, 2020
geometry
Problem Statement
One right pyramid has a base that is a regular hexagon with side length , and the height of the pyramid is . Two other right pyramids have bases that are regular hexagons with side length , and the heights of those pyramids are both . The three pyramids sit on a plane so that their bases are adjacent to each other and meet at a single common vertex. A sphere with radius rests above the plane supported by these three pyramids. The distance that the center of the sphere is from the plane can be written as , where , and are relatively prime positive integers, and is not divisible by the square of any prime. Find .