Lesson Note for Primary 6
Lesson Note on Mathematics
Subject: Mathematics
Theme: Area
Topic: Area of a Circle
Sub Topic: Deriving the Formula for area of a circle
Date: dd/mm/yyyy
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
A plane curve everywhere equidistant from a given fixed point, the centre.
Derive the formula for the area of a circle
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
= πrᶺ2
Rationale:
The concept of the area of a circle is useful and applicable in daily reallife 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 Cutout.
Reference Materials:
Online resources
 Area of a Circle
Lesson Development:
STAGE  TEACHER'S ACTIVITY  LEARNER'S ACTIVITY  LEARNING POINTS 
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 

STEP 1 5mins. Development  provide learners with circular cutout  Students identify parts of the circle.  Recognize circumference, diameter, radius and sectors 
STEP 2 7mins  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. 
STEP 3 8mins  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 cutouts with the glue on the manila cards as shown   (In groups) describe the figure they have formed
 state and name the height(width) of the figure as the radius of the circle.
 state and name the length as onehalf the circumference of the circle = 1/2 circumference
= 1/2 (2πr) = πr  derive the area of the rectangle formed using the length (πr) and the width (r) as
A = Length x width = πr x r = πrᶺ2
 (In groups) discuss the relationship between the figure formed and the circle
  Forming a rectangle with the sectors of a circle.
Recognize a semicircle (e.g. shaded part) as half of the circumference  The figure formed with the sectors of the circle looks like a rectangle Recognize that:
 Height or width = radius (r) of the circle and
 Length as half circumference of circle = πr
Area of circle = πr x r = πrᶺ2
 The figure formed has the same area as that of the circle


EVALUATION 5mins  The teacher guide learners to solve the following problems. Calculate the area of a circle whose radius is 20cm
 1.5m (take π = 22/7)
 Area (A) of a circle = πrᶺ2  But 1cm = 0.01m
Therefore 20cm = 20 x 0.01 = 0.2m Therefore A = 22/7 x (0.2)ᶺ2 = 0.125mᶺ2  A = 22/7 x (1.5)ᶺ2
= 7.017mᶺ2  Asking the learners questions to assess the achievement of the set objectives. 
CONCLUSION 2mins  What is the formula for the area of a circle  A = πrᶺ2  Improving their level of understanding of the Area of a circle. 

ASSIGNMENT   If the circumference of a circular plate is 600cm, find the maximum area it covers on the surface of a dining table. (Take π = 3.14)
 Deriving the Formula for Area of a Circle
Hint:  Cut out the sectors of the circle along the lines
 Arrange the sectors to form a figure such the coloured parts are up and the uncoloured down
 Divide one of the uncoloured sectors into two equal parts and join it to the widths of both sides of the figure and stick all the cutouts sectors with the glue on the manila cards.
 Describe the figure formed after arranging the sectors
 What is the:
 Height of the figure?
 Length of the figure?
 Area of the figure formed?
 What is the relationship between the figure formed and the circle?
 If the circumference of a circular plate is 600cm, find the maximum area it covers on the surface of a dining table. (Take π = 3.14)
 Students solve other problems.  Improving their level of understanding of the Area of a circle. 
Free Will Donation
We know times are tough right now, but if you could donate and support us, be rest assured that your great contributions are immensely appreciated and will be for the progress of our work to help us pay for the server cost, domain renewal, and other maintenance costs of the site. Nothing is too small; nothing is too little.
Account Details
BANK: UNITED BANK FOR AFRICA PLC
ACCOUNT NAME: OFAGBE GODSPOWER GEORGE
ACCOUNT NUMBER: 2250582550
SWIFT CODE: UNAFNGLA
ACCOUNT TYPE: SAVINGS
CURRENCY: DOLLAR (USD) ACCOUNT
ADDRESS: 1. M. Aruna Close, Ughelli, Delta State, Nigeria
PHONE: +234805 5084784, +234803 5586470
BANK: UNITED BANK FOR AFRICA Plc (UBA)
ACCOUNT NAME: OFAGBE GODSPOWER GEORGE
ACCOUNT NUMBER: 2042116266
SORT CODE: 033243371
ACCOUNT TYPE: SAVINGS
CURRENCY: NAIRA ACCOUNT
ADDRESS: 1. M. Aruna Close, Ughelli, Delta State, Nigeria
PHONE: +234805 5084784, +234803 5586470
Your active support gives strength to our Team and inspires to work. Each donated dollar is not only money for us, but it is also the confidence that you really need our project!
AseiClass is a nonprofit project that exists at its founders' expense, it will be difficult to achieve our goals without your help.
Please consider making a donation.
Thank you.
AseiClass Team
Facts about Teachers
● ● ● Teachers Are Great No Controversy.
● ● ● Teachers are like candles, they burn themselves to light others.
● ● ● Teachers don't teach for the money.
● ● ● Every great mind was once taught by some brilliant teachers.
● ● ● Teachers are the second parents we have.
● ● ● If you can write your name, thank your teacher.
Teaching slogans
● ● ● Until the learner learns the teacher has not taught.
● ● ● I hear and forget, I see and remember, I do and know.
● ● ● The good teacher explains. The superior teacher demonstrates. The great teacher inspires.
We provide educational resources/materials, curriculum guide, syllabus, scheme of work, lesson note & plan, waec, jamb, Olevel & advance level GCE lessons/tutorial classes, on various topics, subjects, career, disciplines & department etc. for all the Class of Learners