Understanding Angles for Grade 6

Front

Acute Angle

Back

Less than 90°

Front

Right Angle

Back

Exactly 90°

Front

Obtuse Angle

Back

Between 90° and 180°

Front

Straight Angle

Back

Exactly 180°

Front

Reflex Angle

Back

Between 180° and 360°

Front

Full Rotation

Back

Exactly 360°

Front

Protractor

Back

Tool to measure angles

Front

Degrees

Back

Unit of angle measurement

Front

Complementary Angles

Back

Sum to 90°

Front

Supplementary Angles

Back

Sum to 180°