Area Of Trapezium
Chapter Name : Mensuration |
Sub Topic Code : 104_08_11_02_01 |
Topic Name : Area Of Trapezium |
|
Sub Topic Name : Area Of Trapezium |
|
Introduction
If a plot is by the side of a main road and only two of the sides are regular parallel lines, then it is possible to measure this area because it is in the shape of a trapezium
Pre-Requisites:
Areas of triangles & Rectangles
Activity:
Draw three trapeziums that are equal in perimeter but different in area
Real Life Question:
How is the area of the embankment roads calculated?
Key Words / FlashCards
| Key Words | Definitions (pref. in our own words) |
|---|---|
| Trapezium | A quadrilateral figure that has one pair of parallel lines |
Learning aids / Gadgets
| Gadgets | How it can be used |
|---|---|
| Drawing sheet | On the Drawing sheet, draw a large trapezium of your choice. Divide into one rectangle & a triangle. Calculate the individual areas and sum them up. Also, calculate the area of the trapezium using the formula and verify that both the answers should be same |
Real life uses :
Many important objects around us are in irregular shapes. Trapezium is an important quadrilateral that can be used while finding areas of these objects dividing them into least possible areas. For instance, ship is almost a trapezoid, except for the bottom ends which are slightly curved
Places to visit :
Draw three trapeziums that are equal in perimeter but different in area
Practical examples around us
| Examples | Explainations |
|---|---|
| House in a village | Ever seen the roof of a house in the village? From front view & side views, it will look like a trapezium |
| Dam | Hopefully you have seen a dam. Most of them are trapezium shaped when looked from the side view |
What you learn in Theory:
Area of a trapezium = ½ h (a + b) where a & b are the lengths of the parallel lines & d is the distance between them. Congruent figures are equal in area.
What you learn in Practice:
• The formula can be practically applied to trapezium shaped objects around us • Trapeziums that have different areas & same perimeters can be drawn