4 Work out the perimeter of both shapes in Q3. Key point 5 a What are the other side lengths of this square? b Work out the perimeter. The perimeter is the total distance around the edge of a shape. Add the lengths of all the sides to work out the perimeter of a shape. 8 cm Discussion What is a quick way to work out the perimeter of a square? 6 A square jacuzzi has a side of 4.7 m. Work out its perimeter. 7 a What are the other side lengths of this rectangle? b Work out the perimeter. Discussion What is a quick way to work out the perimeter of a rectangle? 5 cm Q6 Strategy hint Sketch and label the square. 3 cm Q8 Strategy hint 8 A baking tray is 46.5 cm by 33.2 cm. Work out its perimeter. Sketch and label the rectangle. 9 These shapes are drawn on centimetre squared paper. Work out the perimeter of each shape. a b c Q9 hint d The side of each grid square is 1 cm long. 10 a Find the other side lengths of this regular pentagon. b Work out the perimeter. Discussion What is a quick way to work out the perimeter of a regular polygon? 2 cm 11 Work out the perimeter of a a regular hexagon with a side of 4 cm b a regular octagon with a side of 10 mm c a regular nonagon with a side of 50 cm. 12 A 50p coin has the shape of a heptagon. Each edge is 1.2 cm long. Find its perimeter. 13 These shapes have been made by joining rectangles together. 10 cm A 4 cm B a 2 cm 10 cm 4 cm C 5 mm 5 mm 3 cm b 3 mm 5 cm 3 cm 12 mm 3 cm 10 cm 7 mm 4 cm a For shape A, write down the length of i side a ii side b. b Work out the perimeter of shape A. c Work out the missing lengths and the perimeter of the other two shapes. Q13a hint Opposite sides of a rectangle are equal. Unit 8 Measuring and shapes 206