Exploring Angles

What is the measure of each angle in an equilateral triangle?

• 30 degrees

• 90 degrees

• 45 degrees

• 60 degrees

Which angles are right angles? Choose all that apply.

• Angle CDA

• Angle ADE

• Angle BFG

• Angle GFD

Name the angle.

• right angle

• obtuse angle

• acute angle

• straight angle

• reflex angle

Answer explanation

This angle is large than 180 degrees, therefore it is a reflex angle.

Name the angle.

• right angle

• obtuse angle

• acute angle

• straight angle

• reflex angle

Answer explanation

This angle is large than 180 degrees, therefore it is a reflex angle.

Name the angle.

• right angle

• obtuse angle

• acute angle

• straight angle

• reflex angle

Answer explanation

This angle is large than 180 degrees, therefore it is a reflex angle.

If a triangle has angles of 50° and 60°, what is the measure of the third angle?

• 80°

• 100°

• 70°

• 90°

What is the measure of each interior angle of a regular pentagon?

• 120 degrees

• 108 degrees

• 135 degrees

• 90 degrees

How many degrees are in the interior angles of a decagon?

• 360 degrees

• 1440 degrees

• 720 degrees

• 1080 degrees

If one angle of a triangle is 90°, what type of triangle is it?

• Acute triangle

• Right triangle

• Scalene triangle

• Obtuse triangle

Calculate the measure of each interior angle of a regular octagon.

• 135°

• 120°

• 90°

• 150°