Area of Compound Shapes
This topic covers 5 learning steps, guiding your child from the basics through to confident problem-solving. Each step includes a worked example and adaptive practice questions.
What Your Child Will Learn
- Splitting Shapes
Break compound shapes into rectangles - L-Shapes
Calculate area of L-shaped figures - T-Shapes and U-Shapes
Calculate area of more complex compound shapes - Subtraction Method
Find area by subtracting a cut-out from a larger rectangle - Challenge — Complex Compound Shapes
Multi-step compound shape problems
Before This Topic
Your child should be comfortable with:
- Area of Rectangles (Year 4)
- Perimeter of Rectangles (Year 4)
Common Mistakes
- Trying to use a single length × width calculation for an L-shaped or T-shaped figure
Compound shapes must be split into simpler rectangles. Draw lines to divide the shape, find the area of each rectangle, then add them together. There is often more than one way to split the shape — the total area is the same either way. - Using the wrong dimensions when the shape is split (picking lengths that do not match the correct rectangle)
Label every length carefully. When you split a shape, some dimensions need to be worked out by subtracting. For example, if the overall width is 10 cm and one part is 4 cm, the other part must be 6 cm.
Tips for Parents
- Draw L-shapes on squared paper. First count all the squares (the area), then show how splitting into rectangles and multiplying gives the same answer faster.
- Find compound shapes around the house: an L-shaped room, a T-shaped garden. Sketch them, measure, and calculate the area together.
- Practise splitting shapes in different ways and check that the total area is always the same — this builds confidence in the method.
- Use sticky notes to cover a compound-shaped area (like a desk with a notch). Count the sticky notes — that is the area in "sticky-note units."
Key Words
- Compound shape — A shape made up of two or more simpler shapes joined together — like an L-shape or T-shape.
- Decompose — Split a compound shape into simpler shapes (usually rectangles) to calculate the area.
- Area — The amount of space inside a flat shape — measured in square units (cm² or m²).
- Rectilinear — A shape made of straight lines that meet at right angles — all the corners are 90°.
Where This Fits
Before this topic: Children should calculate the area of rectangles using length × width and be comfortable with multiplication.
After this topic: Compound areas lead to calculating the area of triangles, parallelograms, and circles, and to solving real-world area problems in Year 6 and beyond.
How MathCraft Teaches This
In MathCraft, Area of Compound Shapes is taught through the Geometry & Shape adventure track. Your child follows guided lessons with friendly characters, works through examples step by step, then practises with questions that adapt to their level.
The adaptive engine tracks mastery across all 5 steps, revisiting concepts your child finds tricky and advancing when they're ready. Parents can see detailed progress in the Parent Dashboard.
Practise Area of Compound Shapes with MathCraft
Step-by-step lessons, worked examples, and adaptive practice — all wrapped in an adventure game your child will love.
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