Practice Area of Compound Shapes for 11+ | EEZY BREEZY MATHS
21 October 2026
Breaking down compound shapes
Compound shapes are made by joining two or more simple shapes, such as rectangles and triangles. To find the area, split the compound shape into separate parts that are easier to work with.
Calculate each area separately
Work out the area of each part using the correct formula. For rectangles, multiply length by width. For triangles, use 1/2 × base × height. Make sure you use the right measurements for each shape.
Add the areas together
Once you have calculated the area of each part, add them together to get the total area of the compound shape. If there are any overlapping or missing sections, adjust your calculation as needed.
Worked example
A compound shape is made from a rectangle and a triangle. The rectangle is 5 cm by 4 cm. The triangle has a base of 3 cm and a height of 4 cm.
First, find the area of the rectangle: 5 × 4 = 20 cm²
Next, find the area of the triangle: 1/2 × 3 × 4 = 1/2 × 12 = 6 cm²
Add the two areas: 20 cm² + 6 cm² = 26 cm²
The total area of the compound shape is 26 cm².
Check your answers
Encourage your child to double-check their calculations and make sure all parts of the shape have been included. Drawing lines to separate each section can help avoid missing any areas.
Key insight: Splitting complex shapes into simple rectangles and triangles makes the problem much more manageable. Remind your child to label each part clearly and use the correct formula for each shape.
