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Geom Lession 11.2
Lesson 11.2 Extra Notes on the Areas of Regular Polygons
| Question | Answer |
|---|---|
| Area of a triangle = | ½ bh where b is the base and a is the altitude perpendicular to that base |
| The radius of a polygon is the same as the radius a what? | circle |
| The endpoints of a radius are the what? | the center and a vertex of the polygon. |
| Every radius in the same polygon or circle is | congruent |
| Since the radii are all the same and each radius is a side of a triangle in the regular polygon, then? | The two consecutive radii are the legs of an isosceles triangle. |
| Every n-gon can be divided into what? | n congruent isosceles triangles. (n = number of sides) |
| The area of any regular polygon is what? | n times the area of one of those isosceles triangles. |
| The apothem of a regular polygon is the same as what? | The same as the altitude as the isosceles triangle. |
| The endpoints of the apothem are what? | The center of the polygon and the midpoint of a side. |
| Area of a regular polygon = | n(area of a triangle) |
| where n = | number of sides |
| (Area of any Regular Polygon) The base b of the triangle is what? | the same as the side s of the polygon. |
| The height h of the triangle is what? | the same as the apothem a of the polygon. |
| A = ? | n ∙ (area of the isosceles triangle) or n ∙ ( ½ b ∙ h) or n ∙ ( ½ s ∙ a) or ½ a ∙ ns or ½ a ∙ P where P is the Perimeter of the polygon |