Honors Geometry
Name________________________
11.5: Area of Regular Polygons
Recap: What is the formula for an equilateral triangle?
Every regular polygon can be inscribed in a circle and circumscribed about a circle.
Both circle are concentric
The radius of the big circle is the radius of the
polygon
The radius of the small circle is “the apothem” of
the polygon
All triangles formed inside are isosceles
The apothem is perpendicular to the side of the
polygon
Area Formula of any Polygon =
Ex 1: Find the area of a regular hexagon with radius 10.
Ex 2: Find the area of a regular triangle with apothem 8.
Ex 3: Find the area of a regular octagon with sides length of 14.
Ex 4: Find the area of a regular pentagon with apothem 5.
Ex 5: Find the area of a regular hexagon with apothem 8.
Ex 6: Find the shaded area if radius of the circle is 10.