What is Pentagon ?
A pentagon is a 5-sided Polygon.
- A regular pentagon has five lines of reflectional symmetry, and rotational symmetry of order 5 (through 72°, 144°, 216° and 288°).
- A convex pentagon has no angles pointing inwards.
- More precisely, no internal angles can be more than 180°.
- When any internal angle is greater than 180° it is concave.
Properties of a Regular Pentagon
- Interior Angles of 108°
- Exterior Angles of 72°
- Area of approximately 1.7204774 × s × s (where, s = side length)
Types of Pentagon
There are two types of pentagon on the basis of sides and angles:
- Regular pentagon
- Irregular pentagon
Regular pentagon:
- A pentagon which has all five sides equal in length and eventually, all the five angles are equal in measure, is known as regular pentagon.
- Each interior angle of a regular pentagon is 1080.
Irregular pentagon:
- An irregular pentagon is a pentagon which does not have all sides equal.
- Also, it does not have all angles equal.
- Convex pentagon
- Concave pentagon
Convex pentagon
- Convex pentagon is a pentagon in which all five vertices are outwards
Concave pentagon
- A pentagon that has atleast one vertex pointing inwards is called a concave pentagon.
