Area and perimeter
Answers are for parents and teachers.
1
Find the perimeter and the area of a rectangle 15 m long and 8 m wide.
P = 2 × (15 + 8) = 46 m. A = 15 × 8 = 120 m².
2
A rectangular field has an area of 360 m² and a width of 12 m. How long is the fence around it?
Length = 360 ÷ 12 = 30 m. Fence: 2 × (30 + 12) = 84 m.
3
Find the area of this L-shape: a 10 m by 4 m rectangle with a 4 m by 3 m rectangle on top.
40 + 12 = 52 m².
4
A square has a perimeter of 40 m. Find its area.
Side 40 ÷ 4 = 10 m. Area 10 × 10 = 100 m².
5
A rectangle is 5 cm by 3 cm. Double both sides. Find the old and new perimeters and areas.
Old: P = 16 cm, A = 15 cm². New (10 by 6): P = 32 cm, A = 60 cm². The perimeter is doubled and the area is 4 times as big.