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Year 10
Foundation

Checking and securing understanding of area for compound shapes

I can calculate the area of compound shapes made from rectangles, triangles, parallelograms and trapeziums efficiently.

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New
New
Year 10
Foundation

Checking and securing understanding of area for compound shapes

I can calculate the area of compound shapes made from rectangles, triangles, parallelograms and trapeziums efficiently.

Download all resources
Share activities with pupils

Lesson details

Key learning points

  1. There are multiple ways to find the area of compound shapes.
  2. The most efficient method may depend on the features of the shape.
  3. A method is to break the shape into shapes you can find the area of.
  4. A method is to complete the shape.
  5. A method is to rearrange the shape.

Common misconception

Pupils may multiply all given lengths.

Remind pupils that area is found by multiplying two perpendicular lengths from the shape and in some cases a coefficient (half for a triangle, pi for a circle). Trapeziums use the mean length of the parallel sides (one length).

Keywords

  • Area - The area is the size of the surface and states the number of unit squares needed to completely cover that surface.

  • Compound shape - A compound shape is a shape created using two or more basic shapes.

  • Composite shape - A composite shape is an alternative for a compound shape.

Encourage discussion about the three methods for finding the area and the potential of a combination of them. Pupils should aim to be confident with all of them so they can utilise the most efficient.
Teacher tip

Licence

This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).

Video

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Starter quiz

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6 Questions

Q1.
The area is the size of the surface and states the number of unit needed to completely cover that surface.
Correct Answer: squares
Q2.
The area of this rectangle is cm².
An image in a quiz
Correct Answer: 11.76
Q3.
The area of this parallelogram is cm².
An image in a quiz
Correct Answer: 13.25
Q4.
The area of this triangle is cm².
An image in a quiz
Correct Answer: 88
Q5.
The length of the edge marked 'b' is cm.
An image in a quiz
Correct Answer: 8, eight
Q6.
Which of these shapes has a different area to the other three?
An image in a quiz
Correct Answer: An image in a quiz
An image in a quiz
An image in a quiz
An image in a quiz

Exit quiz

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6 Questions

Q1.
A composite rectilinear shape is a composite shape made from .
Correct Answer: rectangles
Q2.
Laura uses the calculation 3 × 1.5 + 11 × 4 to work out the area of this composite rectilinear shape. Which diagram shows the way that Laura has subdivided the shape?
Correct Answer: An image in a quiz
An image in a quiz
An image in a quiz
An image in a quiz
Q3.
This compound rectilinear shape has been completed to make a rectangle. The additional rectangle has an area of cm².
An image in a quiz
Correct Answer: 80, eighty
Q4.
This compound rectilinear shape has been completed to make a rectangle. Which of the following calculations are correct for finding the area of this composite rectilinear shape?
An image in a quiz
18 × 24 + 16 × 5
16 × 5 − 18 × 24
Correct answer: 18 × 24 − 16 × 5
18 × 8 + 24 × 13
Q5.
By rearranging the area, this compound shape is equivalent to ...
An image in a quiz
...a rectangle with dimensions of 20 m by 12 m
Correct answer: ...a rectangle with dimensions of 19 m by 12 m
Correct answer: ...a rectangle with area of 228 m²
...a rectangle with area of 240 m²
Q6.
The area of this compound shape is cm².
An image in a quiz
Correct Answer: 315