1. 6 Measuring length and distance Foundation exercise P.55 1.The distance between the two places on the map is : 6.7 cm (Linear distance) The map scale is : 1 : 20 000 1 cm to 200 m ∴ The distance on the ground is : 200 m  6.7 = 1 340 m (1.34 km)

2. 2.The length of Deep Bay Road on the map is 5 cm. The map scale is : 1 : 20 000 1 cm to 200 m ∴ The length of Deep Bay Road on the ground is : 200 m  5 = 1 000 m 3. a)The length of the river on the map is 11.5 cm. The map scale is : 1 : 20 000 1 cm to 200 m ∴ The length of the river on the ground is : 200 m  11.5 = 2 300 m b)The distance on the map is : 10.8 cm (Linear distance) The map scale is : 1 : 20 000 1 cm to 200 m ∴ The distance on the ground is : 200 m  10.8 = 2 160 m c)With reference to 2b), the length of the river is 2 300 m. ∴ The number of hours need to complete the journey is : 2 300 m  5m = 460 minutes = 7.67 hours (i.e. 460 minutes  60 minutes)

3. 4.The longest section of the park on the map is 4.2 cm. (Refer to right diagram.) The map scale is : 1 : 20 000 1 cm to 200 m ∴ The longest section of the park is : 200 m  4.2 = 840 m 5. a)The length of the light transit railway on the map is 5.5 cm The map scale is : 1 : 20 000 1 cm to 200 m ∴ The length of the light transit railway on the ground is : 200 m  5.5 = 1 100 m b)With reference to 5a), the length of the railway is 1 100 m. ∴ The time needed to complete the journey is : 1 100 m  60 km = 1 100 m  60 000 m = 0.0183 hour = 1.1 minutes (i.e. 60 minutes  0.0183)