# ANGLES IN A POLYGON

CONTENT

1. Definition of Polygons
2. Types Of Polygons
3. Sum of Interior Angles in a Polygon
4. Sum of Exterior Angles in a Polygon

## Definition of Polygons

A closed plane figure bounded by straight lines (edges) is called a polygon. The number of sides of a polygon determines its names. The table below describes the names of polygons according to the number of their sides:

## Types Of Polygons

### 1. Convex Polygon:

A convex polygon has all its interior angles pointing outwards. No angle is pointing inwards. Each internal angle of a convex polygon is always less than 1800. A polygon is convex if any line segment joining any two points on it stays inside the polygon itself. Examples of convex polygons are shown below: ### 2. Concave (Re-entrant) Polygon:

If there is any internal angle greater than 180°, the angle points inwards and the polygon becomes concave.

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