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11-4 Areas of Regular Polygons. 11.4 Areas of Regular Polygons. Area of a Regular Polygon. Vocab : Center – in the center Radius - to a vertex Central angle –from 2 radii Apothem –perpendicular from center to side. Areas of Regular Polygons. Area of a Regular Polygon.
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11.4 Areas of Regular Polygons • Area of a Regular Polygon Vocab: Center – in the center Radius - to a vertex Central angle –from 2 radii Apothem –perpendicular from center to side
Areas of Regular Polygons • Area of a Regular Polygon
Areas of Regular Polygons • Area of a Regular Polygon • Area = (area of the ) x (# of ’s)
Areas of Regular Polygons • Area of a Regular Pentagon • Area = (area of the ) x (# of ’s) • Area = ( ½ apothem x side length) x (number of sides)
Areas of Regular Polygons • Area of a Regular Pentagon • Area = (area of the ) x (# of ’s) • Area = ( ½ apothem x side length) x (number of sides)
Areas of Regular Polygons • Area of a Regular Pentagon • Area = (½ apothem x side length) x (number of sides) • Area = ½ apothem x Perimeter
Areas of Regular Polygons • Theorem 11.6 • The area of a regular n-gon with side length s is half the product of the apothem a and the perimeter P • A = ½ aP • OR • A = ½ a x ns
Areas of Regular Polygons • Area of a Regular Polygon • How to figure out the apothem
Areas of Regular Polygons • Area of a Regular Polygon • How to figure out the apothem C A B
Areas of Regular Polygons • Area of a Regular Polygon • How to figure out the apothem • P-Thag Theorem C Apothem B
Areas of Regular Polygons • Area of a Regular Polygon • How to figure out the apothem • tan x = __B__ • apothem x° C Apothem B
Areas of Regular Polygons • Area of a Regular Polygon • How to figure out the apothem • tan x = __B__ • apothem • Apothem =_ B__ • tan x x° C Apothem B
Areas of Regular Polygons • Area of a Regular Polygon • How to figure out the apothem • cos x = apothem • C • Apothem = cos x • C x° C Apothem B
SPICSA P 443 1-12all, 14,16