Angle Sums of Polygons

Angles in Polygons

The exterior angles of a polygon add up to 360^o

Multiple Choice

The exterior angles of a polygon add up to...

• 360^o

• 180^o

• 200^o

• 90^o

Multiple Choice

What is the size of angle a?

• 72

• 55

• 50

• 53

Multiple Choice

What is the size of the exterior angle of a pentagon?

• 100^o

• 360^o

• 72^o

• 180^o

Multiple Choice

What is the size of the exterior angle of a hexagon (six sides) ?

• 360^o

• 50^o

• 60^o

• 180^o

Multiple Choice

What is the size of one exterior angle of a decagon (10 sides) ?

• 90

• 180

• 360

• 36

Multiple Choice

The exterior angle of a regular polygon is 120^o. How many sides does this polygon have?

• 3 sides

• 4 sides

• 5 sides

• 6 sides

Sum of Interior Angles of a Polygon

Use the formula 180n-360, where n is the number of sides of the polygon

Finding the missing angle

First use the formula 180n-360 to find the sum of interior angles. Then add the other angles and subtract to find the missing angle.

Multiple Choice

Work out the missing angle

• 92

• 88

• 103

• 360

Multiple Choice

Find the value of the missing angle

• 96

• 86

• 120

• 116

Multiple Choice

Find the value of the missing angle

• 83

• 112

• 132

• 118

Multiple Choice

Find the value of the missing angle

• 140

• 156

• 132

• 162

Interior angles of regular polygons

Find the sum of interior angles using the formula 180n-360 as before. Then divide by the number of sides to find the value of one angle.

Multiple Choice

Work out the size of one interior angle of this regular hexagon

• 120

• 720

• 100

• 360

Multiple Choice

Work out the size of one interior angle of this regular heptagon

• 143.56

• 130.5

• 128.57

• 150.54

Multiple Choice

Work out the size of each interior angle of this decagon

• 150

• 130

• 144

• 154