1 / 11

11.3 Areas of Regular Polygons & Circles

11.3 Areas of Regular Polygons & Circles. Objectives =]. Learn how to find the area of polygons & Find area of circles. Area of Regular Polygons.

kaiya
Télécharger la présentation

11.3 Areas of Regular Polygons & Circles

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. 11.3 Areas of Regular Polygons & Circles

  2. Objectives =] Learn how to find the area of polygons & Find area of circles

  3. Area of Regular Polygons • In regular hexagon ABCDEF inscribed in circle G, GA and GF are radii, from the center of the circle to two vertices of the hexagon. GH is perpendicular to AF. This segment is called a Apothem.

  4. APOTHEM ::Definition:: A segment that is drawn from the center of a regular polygon perpendicular to a side of the polygon.

  5. To Find the Area • The area of a hexagon is determined by adding the areas of the triangles. • GH is perpendicular to AF, it is an altitude of AGF. a represents the length of GH and let s represent the length of a side of the hexagon. • Area of triangle AGF ½ bh = 1/2 sa

  6. The area of one triangle is (½)(side)(apothem) sq. units. So the area of the hexagon is 6(1/2 sa) sq. units. The perimeter of the hexagon is 6s units. You can substitute P for 6s in the area formula. SOO instead of…. A = 6(1/2 sa) its… A = 1/2(Perimeter)(apothem) **This formula can be used for any regular hexagon**

  7. Ex. 1 • Find the area of the pentagon with a perimeter of 40 centimeters.

  8. Ex. 2 Find the area of the Octagon. The apothem is 5

  9. Area of a Circle • If a circle has an area of A square units and a radius of r units than A=pi.r squared

  10. Ex. 3 Find the area of the circle B if the diameter is 10. round to nearest tenth.

  11. ASSIGNMENT =] Pg. 613:: # 8-22 Pg 614:: # 30 & 31 , # 36 & 37 Pg 615:: #40

More Related