Determine the RF on the scale:
A length of 3 km on the ground is presented via 6 cm length on a map. Determine the RF on the scale on that it has been drawn.
RF = Length of drawing/ Length of object
= 6 cm/(3 × 1000 × 100 cm)
= 1/(5 × 104)
Example 3
An area of 36 sq km on the ground is presented via an area of 144 sq cm on a map. Find out the RF of the scale for this map.
Now, instead of lengths, area has been provided and we will be committing a mistake whether we get the ratio of areas as RF is a ratio among lengths and not areas. Via a simple unitary process we recognize that 144 sq cm on the map represents 36 sq km on such ground. Getting square root on both the sides so we get 1 cm will represent ¼ sq km or ½ km such
RF = 1 cm/(0.5 × 1000 × 100 cm )
= 1/(0.5 × 105).