Posted by please help on Monday, January 14, 2013 at 8:18pm.
distint points a, b, c, d, e, and f are marked on a circle. How many triangles can be formed using these points as vertices?

geometry  Allyson, Monday, January 14, 2013 at 8:20pm
Draw a circle, form as many triangles as you can, and count.

geometry  please help, Monday, January 14, 2013 at 8:23pm
ok i tried that that its hard why don't u try and tellme the answer ?

geometry  Reiny, Monday, January 14, 2013 at 8:35pm
You have 6 points on a circle.
It is not possible to have 3 of them forming a straight line (not a triangle) so the question becomes how many choices are there of 3 elements form 6
or C(6,3) = 6!/(3!3!) = 20
Answer This Question
Related Questions
 math  There are nine points on a piece of paper. No three of the points are ...
 Math  Six points lie on the circumference of a circle. How many different ...
 Math: Combinations  There are 20 points all in one straight line and 15 others ...
 Geometry  Which one of these is NOT a step used when constructing an inscribed ...
 math algebra help please!  12 points lie on a circumference of a circle how ...
 8th Grade PreAlgebra  Triangle PQR is transformed to triangle P'Q'R'. Triangle...
 analytic geometry/graphing problem  The vertices of a triangle are the points ...
 math  the number of noncollinear points needed to determine a circle Two. The ...
 7th Grade Geometry  A Rectangle with vertices A B C AND D. The triangle is ...
 Geometry  Let A be a convex 61− gon. We then place n points {x i} n i=1 ...
More Related Questions