Lesson Note for Primary 6
Lesson Note on Mathematics
Topic: Area of a Circle
Sub Topic: Deriving the Formula for area of a circle
Class: Basic 6
Duration: 35 Minutes
No of Learners: 30
Learning Objectives:By the end of the lesson learners should be able to:
Say what a circle is
Derive the formula for the area of a circle
A plane curve everywhere equidistant from a given fixed point, the centre.
Rectangle with the sectors of a circle
But, Area of Rectangle = Length x Width
where Length = 1/2 circumference of the circle
= 1/2 x 2πr = πr
Width = radius
Area of the rectangle with the sector of a circle = πr x r
The concept of the area of a circle is useful and applicable in daily real-life activities. The knowledge will assist pupils to understand its application in finding amongst others the base area of wells; pipes; fences; wheels of automobiles and cycles.
Prerequisite skills and knowledge:
- Measurement of lengths of the object including Area of rectangles.
- learners can draw as well as identify parts of a circle particularly the circumference radius, diameter and sectors
- concept of pi (π)
Teaching/ Learning Materials:
Manila cards/Pair of scissors/Glue/starch/Circular Cut-out.
|INTRODUCTION & GROUPING
full class session (3mins)
|Review learners previous knowledge by asking them to find the area of a rectangle (e.g. length 6cm and width 4cm)||(In groups) solve the problem and present their results||Learner’s entry points.
Area of rectangle = length × width
|provide learners with circular cut-out||
Students identify parts of the circle.
|Recognize circumference, diameter, radius and sectors|
|provide pupils in each group the materials mentioned above||
(In groups) cut along the lines of the sectors of the circle to obtain 16 equal sectors
|Different strategies of obtaining sectors.|
|guide learners to divide one of the sectors into two equal parts and join this to the widths of both sides of the figure and stick the all cut-outs with the glue on the manila cards as shown||
|The teacher guide learners to solve the following problems.
Calculate the area of a circle whose radius is
|Area (A) of a circle = πrᶺ2
||Asking the learners questions to assess the achievement of the set objectives.|
|What is the formula for the area of a circle||A = πrᶺ2||Improving their level of understanding of the Area of a circle.|
||Students solve other problems.||Improving their level of understanding of the Area of a circle.|