Polygons
Chapter Name : Understanding Quadrilateral |
Sub Topic Code : 104_08_03_02_02 |
Topic Name : Polygons |
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Sub Topic Name : Diagonals |
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Introduction
The straight line (shortest distance) between two non -consecutive corners of a polygon is called diagonal.
Pre-Requisites:
Basic knowledge about polygons
Activity:
A polygon has different number of diagonals depending on the number of vertices and sides. Draw various polygons and the diagonals in them. Count the number of sides, vertices, and diagonals. Try to establish a relation between them.
Real Life Question:
What is the shortest path to reach an opposite corner from one corner in a square room?
Key Words / FlashCards
| Key Words | Definitions (pref. in our own words) |
|---|---|
| Polygon | A simple closed curve classified according to number of sides and vertices |
| Diagonal | Line joining between two non-consecutive vertices in a polygon |
Learning aids / Gadgets
| Gadgets | How it can be used |
|---|---|
| Scissors, paper, sketches | Polygons are drawn on the paper as plane surfaces increasing one vertex and a side at a time. Diagonals are drawn in each polygon and the number of diagonals can be verified. |
Real life uses :
Computer screens, TV screens, doorways, short paths, constructions
Practical examples around us
| Examples | Explainations |
|---|---|
| Doorways in stations | A doorway is created in a rectangular chamber with two doors placed on the diagonals which rotates, letting people in and out |
| Computer monitors | The screen is measured by the length of the diagonal. A 15.6” screen means that the length of diagonal on screen is 15.6”. |
What you learn in Theory:
An Intro into diagonals in a polygon.
What you learn in Practice:
A polygon is defined by the number of its sides and vertices it has. Depending on their number, a polygon changes shape and is called by other names. Each particular shape will have a different number of diagonals.