10.3 Areas of Regular Polygons

• The radius of a regular polygon is the distance from the center to a vertex.

• The apothem is the perpendicular distance from the center to a side.

Finding Angle Measures• The figure is a regular pentagon with radii and an

apothem drawn. What is the measure of each numbered angle?

Postulate 10.1

• If two figures are congruent, then their areas are equal.

Theorem 10.6

• The area of a regular polygon is half the product of the apothem and the perimeter.

Finding the Area of a Regular Polygon• What is the area of the regular decagon?

p ns10(8)80 .in1

2A ap

1(12.3)(80)2

A2492 .in

More Practice!!!!!

• Homework – Textbook p. 632 #8 – 25 ALL.