center
vertex
center
midpoint
perpendicular
1 ap
2
apothem
perimeter
Practice
p619 #14, 16, 19, 20, 32, 33, 47 [21]
p626 #11, 14, 17, 18, 21, 23, 24, 35
p631 #1, 5, 8­10
100 in2
1: 120
4: 90
7: 60
2: 60
5: 45
8: 30
3: 30
6: 45
9: 60
10­3 Area of Regular Polygons
What is a "Regular" Polygon?
Equilateral AND Equiangular
10­3 Area of Regular Polygons
Radius: Center to Vertex
Apothem: Center to Midpoint
Central Angle
Interior Angle
(n-2)180
n
Interior Angle
Central Angle 45­45­90
30­60­90
Trig
360
n
Central Angle 45­45­90
30­60­90
Trig
(n-2)180
n
360
n
Interior Angle
45­45­90
Central Angle 30­60­90
Trig
(n-2)180
n
Interior Angle
360
n
45­45­90
Central Angle 30­60­90
Trig
(n-2)180
n
360
n
1
A = 2 ap
B
1
= 2 ap
1
B = 2 ap
Find the area of the regular polygon with
the given apothem a and side length s.
dodecagon, a = 26.1 m, s = 14 m
1
B = 2 ap
Find the area of the regular hexagon. Leave
your answer in simplest radical form.
1
B = 2 ap
6m
Find the area of the regular triangle. Leave
your answer in simplest radical form.
1
B = 2 ap
2√ 3 mm
B
1
B = 2 ap
Find B, the area of the Base of this pyramid
1
B = 2 ap
Practice p632 #11­13, 17, 18, 21­23, 35, 44, 45
p638 #1, 2