SOLUTION: 8 points are placed on the line a, 7 points are placed on the line b. How many triangles is it possible to form such that their vertices will be the given points, if a∥b?

Algebra ->  Real-numbers -> SOLUTION: 8 points are placed on the line a, 7 points are placed on the line b. How many triangles is it possible to form such that their vertices will be the given points, if a∥b?      Log On


   

Question 1119818: 8 points are placed on the line a, 7 points are placed on the line b. How many triangles is it possible to form such that their vertices will be the given points, if a∥b?
Answer by ikleyn(52887) About Me  (Show Source):
You can put this solution on YOUR website!
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You have  8%2A%28%287%2A6%29%2F2%29 = 8*21 = 168 triangles having one vertex in line "a" and two vertices in line "b".


Plus you have 7%2A%28%288%2A7%29%2F2%29 = 7*28 = 196 other triangles, having one vertex in the line "b" and 2 vertices in the line "a".


In all, there are 168 + 196 = 364 triangles.

Solved.