Understanding Angles for Grade 8

Front

Definition of angle

Back

Formed by two rays with a common endpoint

Front

Types of angles

Back

Acute, right, obtuse, straight

Front

Acute angle measure

Back

Less than 90°

Front

Right angle measure

Back

Exactly 90°

Front

Obtuse angle measure

Back

Greater than 90° and less than 180°

Front

Straight angle measure

Back

Exactly 180°

Front

Complementary angles

Back

Sum to 90°

Front

Supplementary angles

Back

Sum to 180°

Front

Vertical angles

Back

Opposite angles formed by intersecting lines

Front

Congruent angles

Back

Angles with the same measure