Maths
Maths Wednesday 3rd February 2021
03.02.21
Today we are going to look at area.
Area is the amount of space taken up by the 2D shape.
2D shapes have a width and a length.
When working out area we use the following formula:
Length X Width
Lets use this formula to work of the area of the following rectangle.
So the formula is: Length X Width
Length = 9 cm
Width = 4 cm
Calculation = 9 cm X 4 cm
9 X 4 = 36
9 cm X 4 cm = 36 cm²
Make sure when writing area we use the ² symbol after the unit of measure. e.g cm², mm², km², m² ect.
Lets have a look at a more complicated shape and see how we can work out the area of this shape.
We want to work out the area of the blue shape.
First we want to find the area of the whole shape (including the red)
Lets go back to our original formula:
Length X Width
Length = 6 m
Width = 5 m
Calculation = 6 m X 5 m
6 X 5 = 30
6 m X 5 m = 30 m²
Now we know the whole shape we can subtract the red area.
The red area is taking up 8 m²
30 m² - 8 m² = 22 m²
The blue area = 22 m²
This is how we would work out the area of an irregular shape.
Using these examples to help you go onto Purple Mash and complete the 'Area of Shape' 2Do.