1. May 1, 2017 Area of Regular Polygons
Geometry
May 1, 2017
Area of Regular Polygons

2. Do Now Determine the area of each shape
A rectangle with sides of 7 and 12
A right triangle with legs of 9 and 10
A parallelogram with a base of 14 and an altitude of 12
A trapezoid with bases of 10 and 14 and an altitude of 3.
A kite with diagonals of 13 and 12.

3. I can determine the area and volume of basic shapes and solids.
Chapter Objective
I can determine the area and volume of basic shapes and solids.

4. Today’s Objectives
Area of rhombuses and kites (practice)
Area of regular polygons

5. AREA FORMULAS

6. Basic Parts REGULAR POLYGON: All sides congruent, all angles congruent
RADIUS: Distance from CENTER to VERTEX
APOTHEM (INRADIUS): Distance from CENTER to SIDE

7. Angle Sizes
𝑚∠1= 360° 𝑛 𝑚∠2= 𝑚∠1 2 𝑚∠3=90°−𝑚∠2

8. Angle Sizes
𝑚∠1= 𝑚∠2= 𝑚∠3=

9. Angle Sizes
𝑚∠1= 𝑚∠2= 𝑚∠3=

10. Angle Sizes
𝑚∠7= 𝑚∠8= 𝑚∠9=

11. Area of a Regular Polygon
𝐴= 𝑎𝑝 2 = 𝑛𝑠𝑎 2 a = apothem p = perimeter s = side length n = number of sides

12. Area of a Regular Polygon
𝐴= 𝑎𝑝 2 = 𝑛𝑠𝑎 2

13. Area of a Regular Polygon
𝐴= 𝑎𝑝 2 = 𝑛𝑠𝑎 2