40 likes | 172 Views
10-3 Areas of Regular Polygons. Objective: To find the area of a regular polygon. Essential Understanding : The area of a regular polygon is related to the distance from the center to a side. Review Terms & Formulas. Area of a Rectangle. Polygon vs. Regular Polygon.
E N D
10-3Areas of Regular Polygons Objective: To find the area of a regular polygon Essential Understanding: The area of a regular polygon is related to the distance from the center to a side.
Review Terms & Formulas Area of a Rectangle Polygon vs. Regular Polygon Area of a Triangle A=bh Area of a Parallelogram Area of a Trapezoid A=bh Area of a Kite
Center Radius Apothem: A perpendicular line from the center of the polygon to a side of the polygon a a s Apothem Side s ½ as(6) ½ as(8) Theorem 10-6 Area of a Regular Polygon The area of regular polygon is half the product of the apothem and the perimeter.
ExamplesFind the missing value P = 8s 7 cm 56 in. = 8s 7 in.= s A = ½ asn 6 cm a 140 = ½ a(7)(8) s 140 = (28)a A = ½ asn 5 in. = a P = 56 in. A = 140 in.2 A = ½ (6)(7)(5) A = 105 cm2 p.632:8-20