Complementary, supplementary & vertical angles
Grades 7â8â Acute angle â all 4 relationships apply!
đĩ Complementary
Two angles that add up to 90°
45°
đŖ Supplementary
Two angles that add up to 180°
135°
đĄ Vertical
Opposite angles formed by two intersecting lines â always equal!
45°
đĸ Alternate Interior
When a transversal crosses parallel lines â equal angles on opposite sides
45°
đĄ Remember: Vertical angles are ALWAYS equal. Supplementary angles ALWAYS add to 180°. Complementary angles ALWAYS add to 90°.