1. Area of regular polygons
Section 10.3

2. Find the missing side using trigonometry.

3. A regular polygon means that the polygon is convex and all sides AND angles are congruent.
Area of any regular polygon is: A = ∗P ∗a
A = Area
P = Perimeter
a = apothem

4. In an equilateral triangle, the apothem is NOT half of the altitude.
You can use either A = ½ P a or A = ½ b h

5. Find the area of each regular polygon.

7. Find the area of a regular octagon with perimeter of 72 in.

8. Find the area of the regular pentagon with perimeter of 25 in.

9. Find the area of a regular octagon with perimeter of 96 in.

10. Find the area of the shaded region.
Pentagon and triangle are regular.

11. Find the area of the shaded region.
A regular hexagon located in a square.

12. The area of a regular octagon is 392
The area of a regular octagon is m2 an has an apothem length of 10.9m long.
Find the length of each side.
Find the perimeter of the octagon.

13. Find the area of a square with apothem length of 5 cm.

17. Find the area of the shaded region.