Question

The actual area of an island is 1872km² . On a map, this area is 117 cm². if the length of the coastline is 44cm on the map, find the length of its actual coastline. 

Answer 1

Actual area= 1872 km² 

Area on map represents 117 cm² 

Let 1cm represents x km 

∴ 1cm² represents x × x km² 

Actual area= x × x × 117 km² 

1872 = x² x 117 

`"x"^2 = 1872/117`

x² = 16

x = 4

∴ 1cm represents 4 km 

Length of coastline on map = 44cm 

Actual length of coastline = 44 x 4 km = 176 km