Grade Six Mathematics
Exercise 3
1. What is the perimeter of a rectangle of length 8cm and breadth 4cm? 2. How much wire will be needed to fence a yard 5m long and 3m wide?
3. How much wire will be needed to fence a garden 10m long and 12m wide?
4. Calculate the perimeter of a rectangle of length 12m and breadth 8m. 5. What is the perimeter of a rectangle of length 8cm and breadth 12cm?
You’re doing great! Keep up the good work! Let’s move on.
Now, if we are given the perimeter and breadth of a rectangle, how can we find the length? Let’s find out!
Given the perimeter and the breadth of a rectangle, find the length Formula for Length= (perimeter/2) – Breadth
Example:
If the perimeter of a rectangle is 40cm, and the breadth is 5cm, calculate the length.
Step 1: = 20cm
Step 2: Length= 20cm – 5cm= 15cm
Let’s complete the following table:
Exercise 4
Good job!
Let’s now think about the opposite. If we are given the perimeter and the length of a rectangle, and are asked to find the breadth, what do we do? Let’s find out!
Given the Perimeter and the Length of a rectangle, find the breadth
Formula for breadth= (perimeter/2) – Length
Example: if the perimeter of a rectangle is 24cm, and the length is 9cm, calculate the breadth.
Breadth= (perimeter/2) – Length
Step 1: 24/2= 12
Step 2: Breadth= 12 – 9 = 3cm
As our final activity, let’s complete the following:
Exercise 5 From 5B
1. If the perimeter of a rectangle is 48cm and the length is 4cm, calculate the breadth.
2. If the perimeter of a rectangle is 60cm and the length is 15cm, calculate the breadth.
3. Calculate the breadth of a rectangle if the perimeter is 100cm and the length is 25cm.
4. What is the breadth of a rectangular field if the perimeter is 50m and the length is 10m?
Today’s session concludes, everyone. Return next week to find the solutions to this week’s questions. In our next session, we’ll persist in exploring the perimeter of plane shapes and delve into the concept of their area. Wishing you a fruitful week at school. Goodbye boys and girls!