Measuring the real world

A verandah is a roofed open space beside a house. Its length is 6 m and its breadth is 4 m. A store room is built in one corner. It is 2 m by 2 m. How much open floor is left?

Splitting an odd shape

The open floor is 20 m². Its shape is an L, not a rectangle.

The full outer rectangle is 6 m × 4 m = 24 m². This area includes the store room, which is not open floor.

Instead, cut the real shape into two rectangles. The bottom strip is 6 m × 2 m = 12 m². The top strip is 4 m × 2 m = 8 m². Add them: 12 m² + 8 m² = 20 m² of open floor.

Drag the line to cut the floor. Find the cuts that make two rectangles. The total stays 20 m².

Picking the right unit

Measure a pencil in centimetres. Measure a corridor, a long passage, in metres. The right unit gives an easy number. A 30 m corridor is easier to say than 3000 cm.

Try the lab to finish this lesson.