Some Special Cases
Chapter Name : Practical Geometry |
Sub Topic Code : 104_08_04_03_01 |
Topic Name : Some Special Cases |
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Sub Topic Name : Some Special Cases |
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Introduction
The requirements to draw a quadrilateral.
Pre-Requisites:
Basic knowledge about Quadrilaterals
Activity:
Special cases of quadrilaterals like squares and rectangles and rhombuses can be constructed with less than 5 measurements.
Real Life Question:
Why a four road junction is called square?
Key Words / FlashCards
| Key Words | Definitions (pref. in our own words) |
|---|---|
| Quadrilateral | A simple closed curve with four vertices and four sides |
Learning aids / Gadgets
| Gadgets | How it can be used |
|---|---|
| Rubber bands, marking pins, drawing board, protractor | Mark a point with a pin. Depending on the measurement of sides, make a string using the rubber bands and mark the point where the string ends. Use protractor to measure the included angle and construct the quadrilateral |
Real life uses :
Racks, windows, walls, tiles, boards, table surfaces, cubes, dice, books, pizza boxes, geometry boxes, monitors, frames
Places to visit :
Drawing Room
Practical examples around us
| Examples | Explainations |
|---|---|
| Rubik’s cube | All the surfaces of a rubik’s cube have perfectly equal sides and equal angles. It forms a square |
| Paper | A paper has parallel equal sides and is equiangular. It is in the form of a rectangle. |
What you learn in Theory:
An Intro into the construction of a quadrilateral when three sides and two diagonal are given.
What you learn in Practice:
Four measurements are necessary to make a quadrilateral. But to uniquely define the quadrilateral into its different forms, we need a fifth measurement. However, for special cases like square, rectangle, rhombus we do not need 5 measurements to draw. A square is equilateral and equiangular. So it can be drawn with one measurement of its side. Similarly, A rectangular is equiangular. We can draw it with two measurements.