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.

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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.

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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 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: -
Q:
## How Big Are the Internal Angles on a Regular Decagon?

A: The internal angles of a regular decagon are 144 degrees each. A decagon is a polygon with 10 sides and 10 internal angles, and a regular decagon is a poly... Full Answer >Filed Under: -
Q:
## What Is the Name of a 10-Sided Polygon?

A: The name of a 10-sided polygon is a decagon. The term "decagon" comes from the modern Latin word "decagonum" and from the Greek "dekagonon," which is a com... Full Answer >Filed Under: