Complementary and supplementary angles

Learning Objectives Define complementary and supplementary angles. Identify pairs of complementary and supplementary angles in diagrams. Calculate the measure of a missing complement for a given angle. Calculate the measure of a missing supplement for a given angle. Set up and solve one-step algebraic equations to find unknown angles in complementary and supplementary pairs. Differentiate between complementary and supplementary angle relationships. Have you ever noticed how the hands on a clock form a perfect corner at 3:00? 🕒 That's a special angle we'll explore today! In this tutorial, you will learn about two special angle pairs: complementary and supplementary angles. Understanding how these angles relate to each other is a key building block for all future g...

TermDefinitionExample AngleThe amount of turn between two lines that meet at a common point called the vertex. It is measured in degrees (°).The corner of a square is a 90° angle. Right AngleAn angle that measures exactly 90°. It looks like the letter 'L' and is often marked with a small square in the corner.The angle formed by the floor and a wall is a right angle. Straight AngleAn angle that measures exactly 180°. It forms a perfectly straight line.The angle formed by the hands of a clock at 6:00 is a straight angle. Complementary AnglesTwo angles whose measures add up to exactly 90°.An angle of 30° and an angle of 60° are complementary because 30° + 60° = 90°. Supplementary AnglesTwo angles whose measures add up to exactly 180°.An angle of 110° and an angle of 70° are supplem...

Complementary Angle Rule \angle A + \angle B = 90^{\circ} Use this rule when you know two angles are complementary. If you know one angle, you can find the other by subtracting the known angle from 90°. Supplementary Angle Rule \angle A + \angle B = 180^{\circ} Use this rule when you know two angles are supplementary, such as two angles that form a straight line. Subtract the known angle from 180° to find the missing angle.