7-2 Area of Regular Polygons

A line from the center of a regular polygon at right angles to any of its sides.

$$A = \frac{1}{2} a P$$ where A is the area, a is the apothem, and P is the perimeter.

Use the formula $$A = \frac{1}{2} a P$$ where a is the apothem and P is the perimeter.

The total length of all its sides.

$$A = \frac{1}{2} \times 13 \times (6 \times 15) = 585 \text{ ft}^2$$ .

$$A = \frac{1}{2} \times 8 \times 40 = 160 \text{ cm}^2$$ .

The apothem is shorter than the radius and is used to calculate the area.

$$A = \frac{1}{2} \times 7.5 \times (5 \times 10) = 187.5 \text{ cm}^2$$ .

Use the formula $$A = \frac{1}{2} a P$$ where a is the apothem and P is the perimeter.

$$A = \frac{1}{2} b h$$ where b is the base and h is the height.