2. The sum of the measures of the interior angles of a convex n-gon (n-2)∙180 0. Corollary to Theorem 11.1 The measure of each interior angle of a regular n-gon is

3. Theorem 11.2 – The sum of the measures of the exterior angles of a convex polygon, one angle at each vertex, is 360 0. Corollary to Theorem 11.2 The measure of each exterior angle of a regular n-gon is 1 2 5 4 3

4. Elena is planning a triangular garden. She wants to build a fence around the garden to keep out the deer. The length of one side of the garden is 26 feet. If the angles at the end of this side are 78 0 and 44 0, find the length of fence needed to enclose the garden. 26ft 78 0 44 0 x y The length of the fence is 26+21.3+30 =about 77.3 feet

5. Theorem 11.3 – Area of an Equilateral Triangle The area of an equilateral triangle is one fourth the square of the length of the side time. s s s

6. How many triangles are formed? What kind of triangles are they? Find the area of one of the triangles. What is the area of the entire hexagon? Explain.

7. Theorem 11.4 The area of a regular n-gon with side length s is half the product of the apothem a and the perimeter P, so A = ½ aP, or A = ½ a ∙ ns

8. Find the area of each regular polygon. Show your answers in simplest radical form and rounded to the nearest tenth. A = 128 cm 2