Definitions:
-A polygon is a many sided, planar, enclosed figure that is named according to the number of sides it has.
-An equilateral polygon has all congruent sides
-An equiangular polygon has all congruent angles
-A regular polygon has all sides and angles congruent
-A central angle has a vertex at the center, and sides pass through two consecutive vertices
-A convex polygon has all interior angle measures less than 180 degrees
-A concave polygon has at least one interior angle measure at 180 degrees
# of sides: Name:
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A polygon is named for the number of sides it has. A couple polygons have two names that are acceptable and commonly used.
For polygons with a very large number of sides, you have to mix names together, and add the word AND, which is KAI. For example, to say a polygon with 78 sides, you would call it a "heptacontakaioctagon". The word for hundred is "hecta", so if you wanted to say a polygon with 555 sides, for example, you would call it a "pentahectakaihectacontakaihecatgon". |
The Interior and Exterior AnglesHere's the equation to use if you want to find the SUM of the interior angles of a polygon:
(n-2)(180) For ONE interior angle: the equation abovedivided by n For the SUM of exterior angles in a polygon, it will ALWAYS BE 360 degrees For ONE exterior angle, here's how you find it: (n-2)180 1: 180- ---------- (this line means divided by) n (n-2)180 2: 180n- ---------- n 3: 180n- (n-2)180 ------------------ n 4: 180n-180n+360 ------------------ n Final equation for finding ONE exterior angle: 360 / n |