Interior Angles Polygons

Interior Angles of Polygons

GEOMETRY

Draw

Slide 4

A closed 2D-shape consisting of line segments

Polygons

​Polygons do not include curved sides.
All sides must be connected.

At least one side is different
At least one angle is different

​Irregular

All sides are equal
All angles are equal

​Regular

Polygons

Multiple Choice

Regular Polygons only have equal sides.

• True

• False

Interior Angles

Do you remember the sum of the interior angles of an equilateral triangle?









If all angles are equal in size, then the interior angle = 60°

Multiple Choice

State the sum of the interior angles of a square.

• 180 degrees

• 270 degrees

• 360 degrees

• 450 degrees

Interior Angles

​Step 1

Sum of the interior angles = (n-2) x 180

​n = amount of angles in the polygon

Sum of the interior angles
n

​Step 2

Sum of the interior angles
(3-2) x 180 = 180 degrees

Interior angle
180 : 3 = 60 degrees

​​Triangle

Sum of the interior angles
(4-2) x 180 = 360 degrees

Interior angle
360 : 4 = 90 degrees

​​Square

Fill in the Blanks

Multiple Choice

Knowing that the sum of the interior angles of a hexagon is 720 degrees, calculate the interior angle of a regular hexagon.

• 72 degrees

• 180 degrees

• 90 degrees

• 120 degrees

Multiple Choice

Calculate the interior angle of an octagon.

• 80 degrees

• 135 degrees

• 180 degrees

• 720 degrees

Fill in the Blanks

Interior Angles

​Step 1

Sum of the interior angles = (n-2) x 180

​n = amount of angles in the polygon

Sum of the interior angles
n

​Step 2