Map scale 1 cm : 20 km — find real distance for 4 cm on map
Two cities show up just four centimeters apart on a map. How far apart are they really?
The map's scale tells us: one centimeter on the map stands for twenty real kilometers.
Let's set up a proportion. On the left, the scale itself: one centimeter over twenty kilometers.
On the right, the cities: four centimeters over x — the real distance we want to find.
Cross-multiply: one times x equals twenty times four.
Twenty times four is eighty, so x equals eighty.
The cities are eighty kilometers apart in real life. Scale drawings unlocked!