Q:
# How Many Triangles Are in a Decagon?

**A decagon is a ten-sided, closed-plane figure with eight triangles in it.** These eight triangles are formed by joining any vertex of the decagon to any other vertex. Thus, the triangles are formed by drawing the diagonals of the decagon.

Credit:
ramsd
CC-BY 2.0

The general formula for finding the number of triangles that can be formed is "n-2," where “n” is the number of sides of the polygon.

The sum of the interior angles of a decagon is 1440 degrees, and the exterior angle of a decagon is 36 degrees. The interior angle of a decagon is 144 degrees. It has 35 distinct diagonals that can be drawn for all vertices of the decagon.

Learn more about Shapes-
Q:
## What Is a 10-Sided Polygon Called?

A: A polygon with 10 sides is called a decagon. The word comes from the Greek words for "ten" ("deka") and for "angle" or "corner" ("gonia"). Decagons have 10... Full Answer >Filed Under: -
Q:
## How Many Lines of Symmetry Does a Decagon Have?

A: A regular decagon has 10 lines of symmetry, one line drawn through each vertex and one line drawn through the midpoint of each edge. A line of symmetry ind... Full Answer >Filed Under: -
Q:
## What Shape Has 10 Sides?

A: A shape that has 10 sides is call a decagon. A decagon is a type of polygon, which is a two dimensional shape with straight lines. These lines connect to e... Full Answer >Filed Under: -
Q:
## What Is a 10-Sided Shape Called?

A: A flat 10-sided shape with sides of equal length is called a decagon. A solid 10-sided shape with faces of equal size and shape is called a decahedron. Full Answer >Filed Under: