1. Review of Angles
90˚ 180˚ 270˚ 360˚
Angles are a measure of the amount, or degree of turning from one
line to another around a common point, called the vertex.
degree
vertex
Quarter Turn Half-Turn
Three-Quarter Turn Full-Turn
REMEMBER: a right angle is 90˚.

2. Important Vocabulary
90˚
Copy the above angle and vocabulary into your notebook.
Degree (a measure
for angles)
Vertex
(an endpoint
where two
line segments
or lines come
together)
90˚ = Right Angle

3. Types of Angles

4. Types of Angles
Type of Angle Description
Acute Angle An angle that is less than 90˚
Right Angle An angle that is exactly 90˚
Obtuse Angle An angle that is greater than 90˚ but less than 180˚
Straight Angle An angle that is 180˚ exactly
Reflex Angle An angle that is greater than 180˚
Full Rotation 360˚
Copy the chart above into your notebook.