The gcf of 32 and 72 can be obtained like this: The factors of 32 are 32, 16, 8, 4, 2, 1. The factors of 72 are 72, 36, 24, 18, 12, 9, 8, 6, 4, 3, 2, 1. The common factors of 32 and 72 are 8, 4, 2, 1,
The factors of 32 are 32, 16, 8, 4, 2, 1. The factors of 72 are 72, 36, 24, 18, 12, 9, 8, 6, 4, 3, 2, 1. The common factors of 32 and 72 are 8, 4, 2, 1, intersecting the two sets above.
We know that a quadrilateral needs to have four vertices (or points on the circle). There are always two ways to link the cross — horizontally or vertically. Using my limited knowledge of combinations, we know that choosing four points out of seven equals 35. Multiplying the two ways to connect those lines (again, horizontally and vertically) makes 35*2 = 70 "bow-tie quadrilaterals" that can be formed on the circle using four points. There are 5985 ways four chords can be chosen out of twenty-five chords because C(25,4) equals 5985, so the probability is 70/5985... and then we just need to simplify that fraction.
