
Kathye P. answered 10/02/12
Math Geek, passionate about teaching
Hi, Daisy.
A pentagon is a closed figure with 5 sides and 5 angles. It CAN have right angles and parallel lines, depending on how you draw it!
The home plate in baseball is an example of a pentagon with two right angles and one pair of parallel sides. A famous pentagon is the Pentagon building in Washington, D.C. which houses the Department of Defense. It is an example of a regular pentagon.
A regular pentagon is one that has all sides and all angles congruent. The interior angles of a pentagon add up to 540°, and in a regular pentagon, each angle measures 108°.
Since all sides and angles are congruent, a regular pentagon has a line of symmetry from each vertex; it has 5 lines of symmetry.
Hope this helps!
Kathye
Roger B.
Hi Emmy,
What you wrote only applies to regular pentagons. As Kathye pointed out, not all pentagons are regular.
Roger
04/20/13