A polygon with five sides is called a pentagon. In Greek, "pente" means "five." When math textbooks discuss pentagons, they are typically referring to a polygon with five equal sides, otherwise known as a regular pentago... More »

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A polygon is a plane figure that has "at least three straight sides and angles," according to Oxford Dictionaries. However, polygons can have more than three sides; most have five or more. More »

Hexagons are polygons with six sides (or edges) and six angles (or vertices). They are classified as regular or irregular, as well as convex or concave. More »

A decagon is a polygon that has 10 sides. Decagons can be both regular polygons, which have sides of equal length and equal interior angles between each side, or irregular polygons, which have unequal sides and angles be... More »

www.reference.com Math Geometry

The perimeter of a parallelogram, as for any polygon, is the sum of the lengths of its sides. The opposite sides of a parallelogram are parallel and have the same measurement. The formula for its perimeter is twice the s... More »

According to the University of Washington math department, a regular pentagon has five obtuse angles. The sum of all angles for a regular pentagon is 540 degrees, making each angle 108 degrees. Any angle over 90 degrees ... More »

The interior of a pentagon has five angles totaling 540 degrees. In a regular pentagon – a polygon with five congruent sides and five congruent angles – each angle is 108 degrees. Each exterior angle of a regular pentago... More »