Exterior and interior Angles of a polygon

Exterior Angles

And some questions on interior angles too

Exterior Angles

Angle made when you extend a side of the polygon

Its the angle "outside the circle"

Property #1

The sum of all the exterior angles of ANY polygon is 360° 

  

Multiple Choice

What is the sum of all the exterior angles of an octagon?

• 8

• 360

• 40

• 100

Fill in the Blank

Solution

Add up all the angles:

90 + 60 + 46 + 73 = 269

Subtract from 360:

360 - 269 = 91

answer:

x = 91

Property #2

To find the measure of ONE exterior angle of a REGULAR POLYGON, divide 360 by the number of sides (n)

Fill in the Blank

What is the measure of each exterior angle of a regular hexagon?

Solution

A hexagon has 6 sides:

360/6

answer:

x = 60

Fill in the Blank

What is the measure of an exterior angle of a regular 20-gon?

Multiple Choice

Solve for a.

• 90°

• 180°

• 270°

• 80°

Multiple Choice

What is the sum of exterior angles of a pentagon?

• 180

• 360

• 540

• 760

Multiple Choice

Five angles of a hexagon measure 119°, 129°, 104°, 149°, and 95°.  What is the measure of the sixth angle?

• 89
• 105
• 720
• 124

Multiple Choice

What is the formula for the sum of the interior angles of a polygon?

• S = (n-2)
• S = (n-2) 180
• S = 360 / n
• S = (n-2) 360

Multiple Choice

What is the name of a 7 sided polygon?

• hexagon
• heptagon
• octagon
• nonagon

Multiple Choice

Find the value of X

• 94
• 25
• 36
• 180

Multiple Choice

Find the angle sum of the interior angles of the polygon.

• 180° 
• 540° 
• 720° 
• 1080° 

Multiple Choice

What is the SUM of the angle measures in a nonagon (9 sides)?

• 1440°

• 900°

• 1080°

• 1260°