Remarkable / Worksheets / Grade 7 Maths / Area and perimeter of 2D shapes
A one-page CAPS Grade 7 Maths poster on area and perimeter of 2D shapes (Measurement), with the key ideas, key words and a tip to remember.
The perimeter is the distance around a shape. Add the lengths of all the sides.
A rectangle is 14 cm by 6 cm.
P = 2 × (14 + 6) = 2 × 20 = 40 cm
The area is the space inside a shape. It is measured in square units.
A rectangle is 7 m by 3 m.
A = 7 × 3 = 21 m²
A triangle is half of a rectangle. Use the base and the perpendicular height. They meet at a right angle.
A = ½ × base × height
A = ½ × 10 × 7 = 35 cm²
4 m² = 4 × 10 000 = 40 000 cm²
900 mm² = 900 ÷ 100 = 9 cm²
Count the unit squares inside the shape. Each square has an area of 1 square unit.
13 squares of 1 cm²
A = 13 cm²