PARALLEL AND PERPENDICULAR LINES
Definition Of Parallel And Perpendicular Lines
Parallel Lines are distinct lines lying in the same plane and they never intersect each other. Parallel lines have the same slope. In the figure below, lines PQ and RS are parallel and the lines l and m are parallel.
Perpendicular lines are lines that intersect at right angles. If two lines are perpendicular to each other, then the product of their slopes is equal to - 1. In the figure shown below, the lines AB and EF are perpendicular to each other.
Video Examples: Parallel and Perpendicular Lines
Solved Example on Parallel and Perpendicular Lines
Ques: Find the number of points of intersection for one pair of perpendicular lines.
Choices:
A. 3
B. 0
C. 2
D. 1
Correct Answer: D
Solution:
Step 1: Two lines are said to be perpendicular if they intersect at right angles.
Step 2: Any two perpendicular Lines intersect at exactly one point.
Quick Summary
- Parallel lines never intersect.
- Perpendicular lines intersect at right angles.
- Parallel lines have the same slope.
- The product of the slopes of perpendicular lines is -1.
🍎 Teacher Insights
Use visual aids and real-world examples to illustrate parallel and perpendicular lines. Emphasize the relationship between slopes and the orientation of lines.🎓 Prerequisites
- Basic geometric shapes
- Understanding of angles
- Concept of slope
Check Your Knowledge
Q1: Which of the following describes parallel lines?
Q2: What is the relationship between the slopes of perpendicular lines?
Frequently Asked Questions
Q: How can you tell if two lines are parallel?
A: If two lines have the same slope and different y-intercepts, they are parallel.
Q: How can you tell if two lines are perpendicular?
A: If the product of the slopes of two lines is -1, they are perpendicular.