# What is the arc length formula and how would it be used to find the radius of the earth?

##### 1 Answer

Apr 17, 2016

If arc length (seemingly horizontal distance) between two locations on the equator, with longitude difference

#### Explanation:

The formula used is (circular arc length) = radius X (angle subtended at the center in radian)

Sample data, for explication:

If two locations, near the equator, in Brazil, have longitudes

Equatorial radius