Circles and PiArcs Rad
If the central angle is measured in
arc length | = | |
= |
sector area | = | |
= |
Notice how the equations become much simpler, and π cancels out everywhere. This is because, as you might recall, the definition of radians is basically the length of an arc in a circle with radius 1.
Now let’s see how we can use arcs and sectors to calculate the circumference of the Earth.