Question

A map is drawn to scale of 1:20000. Find: The area of the lake on the map which has an actual area of 12km² 

Answer 1

Scale = 1:20000
area of lake represented on the map:
12 Sq km =12 x (100 x 1000)² [as 1km = 100000cm]
= 12 x 10¹⁰

`"Area(map)"/"Area(land)"` = Scale

`"Area(map)"/(12 xx 10^10) = (1)/(20000)^2`

Area(map) = `(12 xx 10^10)/(20000)^2 = (1200)/(4)`

Area(map) = 300cm².