Any n-sided regular polygon, by joining a single vertex up to each of the others, will have a total of (n - 2) triangles inside. In this case, an 11-sided polygon will contain 11 - 2 = 9 triangles.
pyramid An pyramid is a geometric solid of the shape made famous by the royal tombs of ancient Egypt. It is a solid whose base is a polygon and whose lateral faces are triangles with a common vertex
By drawing all the diagonals from one vertex, the polygon is divided up into triangles. The sum of the interior angles of the polygon is equal to the sum of the internal angles in the triangles. With n vertices, each vertex is not directly connected to n-3 other vertices, thus n-3 diagonals can be drawn from a vertex which will create n-2 triangles (each with the sum of their interior angles as 180o); so: sum_of_interior_angles = 180 x (number_of_sides - 2)
A hexagonal pyramid.
It could be a pyramid shape
I need help with that too!
A pyramid is a solid figure with one face that is a polygon and three or more faces that are triangles with a common vertex. Yeah, pg. 114 in the math workbook is a little hard, and the guy who answered this before me thought it was funny to improve the answer by saying the answer was 45. That's just not mature. I don't get it. Anyway, I hope you finish your homework at this rate.
Two triangles can be formed by the diagonals of one vertex of a four-sided polygon.
A pyramid has a polygonal base with all other sides being triangles. As the Egyptians famously demonstrated, a common pyramid has a square base with four triangles meeting at a vertex, but any polygon - regular or irregular - can be used as the base of such a polyhedron.