Warm Up 04.11.12Week 4

Section 11.1 Day

1

I will find the measures of interior and exterior angles of a polygon.

180⁰ 360⁰ 540⁰ 720⁰

3 sides 4 sides 5 sides 6 sidesEx 1

1•

2 • 180 3 • 180 4 • 180

Ex 2

Polygon Interior Angles Theorem

The sum of the measures of the interior angles of a convex n-gon is ( n – 2 ) • 180⁰.

Theorem 10.15

( 6 – 2 ) • 180⁰

4 • 180⁰

720⁰

136⁰ + 136⁰ + 88⁰ + 142⁰ + 105⁰ + x⁰ = 720⁰

607 + x = 720

x = 113

6

5

4 3

2

1

Ex 3 The measure of each angle of a regular polygon is 140.

How many sides?

Theorem 10.15A

9 sides

Ex 4 Find the value of x for the regular polygon:

x

Assignment:

Textbook Page 665, 14 – 19 all.

Do 1: What is the value of x?