University:
Missouri State University
Course:
MTH 460 | College Geometry
Academic year:

2021
Views:

438

Pages:

23
Author:

Hanusia3lug

Agenda: 1. Warm Up 2. HW Review 3. Section 3.3 Proving Lines Parallel 4. Practice Objective: I can prove lines parallel. Warm - up Directions: If m angle 1 = 50 deg find the measures of the remaining angles. 1 2 3 4 5 6 7 8 m angle2=| 30/(50 ^ 2) m angle 3 = 30 m angle 4 = 50 3-50 m45= m/6= m angle7=\ 20 m angle 8 = 50 Theorem 3-7 - Proof Given: kt; nIt Prove: k II n 2 n 1. kt 1. Given 57 k 2. 5 is a right angle. 2. Definition of perpendicular lines. 3. m/5 = 90 3. Definition of a right angle. 4. nIt 4. Given 5. 22 is a right angle. 5. Definition of perpendicular lines. 6. m/2 = 90 6. Definition of a right angle. 7. m/2 m/5 7. Substitution 8. k ll n 8. Postulate 11 5 Ways to Prove Lines are Parallel 1. Show that corresponding angles are congruent Post. 11 2. Show that alternate interior angles are congruent thm3 3. Show that same side interior angles are supplementary Lexterior thm 3-6 4. In a plane, show that both lines are perpendicular to a third line 5. Show that both lines are parallel to a third line llls Kill, then ///