Composite Area & Perimeter
Split the shape into rectangles, triangles and circles, and add or subtract areas.
The rules
- Draw dividing lines to make simple shapes.
- Area = sum of the parts, or the whole minus the cut-out.
- Perimeter only includes the outer boundary.
- Write the units: area in square units.
Watch out: Including inner edges in the perimeter.
Worked example
A 10 by 6 rectangle has a 2 by 2 square cut from one corner. What is the area?
- Rectangle area: 60.
- Cut-out: 4.
- 60 − 4 = 56.
Answer: 56
Try it yourself
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