11.1 Angles Measures in a Polygon

Sum of the angles in a

Triangle 180°

Quadrilateral 360°

Pentagon 540°

Hexagon ?

How to find the Sum,

Number of sides minus two times 180°

1802n

Remember

Each angle of a Regular Polygon

Regular Polygons have all sides and angles equal.

Each angle would be

n

n 1802

Solve for x

Non regular polygon

x

114

105

102

135

Solve for x

x

114

105

102

135

84

540456

180)25(135114105102

x

x

x

Interior and External Angles of Polygon

The External always add to 360°

Remember

How many sides?

If each interior angle of a regular polygon is 165°. The polygon had how many sides?

If you use the interior angle.

24

15360

165360180

1651802

1651802

n

n

nn

nnn

n

How many sides?

If each interior angle of a regular polygon is 165°. The polygon had how many sides?

If you use the external angle. 15165180

24

15360

15360

n

nn

Solve for y

y2

y2

y

y

Solve for y

y2

y2

y

y

60

3606

36022

y

y

yyyy

Solve for x Regular Hexagon

x

Solve for x Regular Hexagon

x

606

360

6

x

x

n

Homework

5451

4030

246#

667665

Page