How long is the equator line on a 1: 100000000 scale map.

First, it should be clarified that the length of the equator is approximately 40,000 kilometers.
On a map in scale 1: 100000000, 1000 kilometers can be displayed in one centimeter of the map.
This value is obtained by converting kilometers to centimeters.
Since 1 km is 1000 meters.
1000 * 1000 = 1,000,000 meters.
Since 1 meter is 100 centimeters:
1,000,000 * 100 = 100,000,000 centimeters.

In this case, in order to determine the length of the equator line on a given map, the real length of the Equator should be divided by the ratio.
We get:
40,000/1000 = 40 centimeters.