4-3 A Right Angle Theorem Learner Objective: Students will apply a Right Angle Theorem as a way of proving that two angles are right angles and to solve problems involving right angles. Advanced Geometry

Learner Objective: Students will apply a Right Angle Theorem as a way of proving that two angles are right angles and to solve problems involving right angles. Theorem: If two angles are both supplementary and congruent, then they are right angles. p m 1 2 Given: Prove: and are right angles. Proof: Since 1 and 2 form a straight angle (line p), they are supplementary (Def. of Supp. Angles). Therefore m 1 + m 2 = 180. Since 1 2, we can use substitution to get the equation m 1 + m 1 = 180, so 2(m 1) = 180 m 1 = 90 Thus 1 is a right angle (Def. of rt. angle) and so is 2.

Learner Objective: Students will apply a Right Angle Theorem as a way of proving that two angles are right angles and to solve problems involving right angles.

HW Pg. 182 # 1,2,4, 10, 13, 14

Learner Objective: Students will apply a Right Angle Theorem as a way of proving that two angles are right angles and to solve problems involving right angles.

STATEMENTS REASONS

Learner Objective: Students will apply a Right Angle Theorem as a way of proving that two angles are right angles and to solve problems involving right angles.