Slope Of A Line
Chapter Name : Straight Lines |
Sub Topic Code : 104_11_10_02_03 |
Topic Name : Slope Of A Line |
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Sub Topic Name : Conditions For Parallelism And Perpendicularity Of Lines In Terms Of Their Slopes |
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Introduction
Numerous parallel and perpendicular lines can be drawn to a given line if we know the inclination of the line.
Pre-Requisites:
Idea about slope of a line in intercept form and two point form.
Real Life Question:
Is the quadrilateral with vertices A (-2,-1) B(4,0) C(3,3) D(-3,2) a parallelogram?
Key Words / FlashCards
| Key Words | Definitions (pref. in our own words) |
|---|---|
| Parallel Lines | Let m1 be the slope of line l1 and m2 is the slope of line l2. The lines are said to be parallel if m1=m2 |
| Perpendicular Lines | Let m1 be the slope of line l1 and m2 is the slope of line l2. The lines are said to be parallel if m_1=-1/m_2 |
Learning aids / Gadgets
| Gadgets | How it can be used |
|---|---|
| Protractor and Graphs | Draw a line on the graph and draw parallel and perpendicular lines to that line using the protractor. |
Real life uses :
Civil Engineers use the concept of parallel, perpendicular and intersecting lines to develop safe roads and railways.
Practical examples around us
| Examples | Explainations |
|---|---|
| Railway Tracks | Railway Tracks run parallel to each other. |
| Road Crossings | A road crossing is made up of two perpendicular intersecting roads. |
What you learn in Theory:
What are parallel and perpendicular lines?
What you learn in Practice:
How to determine whether two given lines are parallel or perpendicular?