1. Section 11-2 Areas of Regular Polygons

2. Area of an Equilateral Triangle The area of an equilateral triangle is one fourth the square of the length of the side times Formula: or

3. Given any regular polygon, you can circumscribe a circle about it.

5. Parts of a Regular Polygon:

6. Center is the center of the circumscribed circle Example:

7. Radius is the distance from the center to a vertex Example:

8. apothem is the (perpendicular) distance from the center of the polygon to a side. Example:

9. Central angle is an angle formed by two radii drawn to consecutive vertices. Example:

10. To find the Measure of a Central Angle of a Regular Polygon: **n = the number of sides = Central Angle

11. 1

12. To find the area of any regular n-gon: 1.Divide the polygon into congruent triangles 2.Find the area of one of those triangles 3.Multiply that triangle’s area by the number of triangles that are in the polygon

13. Area of a regular polygon The area of a regular polygon is equal to half the product of the perimeter and the apothem. Formula: