AREA OF REGULAR POLYGONSSECTION 10.3

Warm UpFind the unknown side lengths in each special right triangle.

1. a 30°-60°-90° triangle with hypotenuse 2 ft

2. a 45°-45°-90° triangle with leg length 4 in.

3. a 30°-60°-90° triangle with longer leg length 3m

A regular polygon means that the polygon is convex and all sides AND angles are congruent.

Area of any regular polygon is: A = A = Area

P = Perimetera = apothem

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

Find the area of each regular polygon.

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

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

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

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

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

The area of a regular octagon is 392.4 m2 an has an apothem length of 10.9m long.

a. Find the length of each side.

b. Find the perimeter of the octagon.

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

Find the area of the shaded region.