Two triangles can be formed by the diagonals of one vertex of a four-sided polygon.
The number of triangles formed by the diagonals of a 21 sided polygon is C(21,3) = 21x20x19/3x2x1 = 1,330.
There are 8
depends on what shape that vertex is in
It is: 8-2 = 6 triangles
how many triangles are formed when any parallelogram and it diagonals are drawn
5 triangles are formed.
If all of the diagonals are drawn from a vertex of an octagon, how many triangles are formed