Learning

Lessons

1. Basics
2. Deductive Reasoning

3 - Parallel lines

4 - Congruent Triangles

5 - Quadrilaterals

6 - Inequalities

7 - Similar Polygon

8 - Rt. Triangles

9 - Circles

10 - Constructions

11 - Areas of 2D objects

12 - Areas and Volumes

13 - Coordinates

14 - Reflection/Rotation

Perpendicular Lines

Objective:

• To know what perpendicular lines are and to be able to prove it's theorems.

Lesson 2-4 Perpendicular Lines

Perpendicular Lines : Two lines that intersect to form right angles (90º Angles). If there is an intersection with an angle begin 90º then a person can conclude that the intersection is an example of perpendicular lines

Theorem 2-4

If two lines are perpendicular, then they form congruent adjacent angles

Angle 1, Angle 2, Angle 3, and Angle 4 are all congruent adjacent angles.

Theorem 2-5

If two lines form congruent adjacent angles, then the lines are perpendicular.

Angle 1, Angle 2, Angle 3, and Angle 4 are all congruent adjacent angles, therefore the lines are perpendicular.

Theorem 2-6

If the exterior sides of two adjacent acute angles are perpendicular, then the angles are complimentary

Angle ABD and Angle DBC are complimentary angles.