Unit 3
Angles
Acute Angles
An acute angle is an angle measuring between (but not including) 0 and 90
degrees.
The following angles are all acute angles.
Obtuse Angles
An obtuse angle is an angle measuring between (but not including) 90 and 180
degrees.
The following angles are all obtuse.
Unit 3
Right Angles
A right angle is an angle measuring 90 degrees. Tw o lines or line segments that meet at
a right angle are said to be perpendicular.
The follow ing angles are both right angles.
Straight Angle
A straight angle is 180 degrees
This is a straight angle
Reflex Angle
A Reflex Angle is more than 180° but less than 360°
This is a reflex angle
Unit 3