+1005 A circle is 2π radians.
So the angle measure is 0.8/2π = 0.4/π part of the circle.
The circle has circumference 2π20 = 40π
So thus...
We multiply 0.4/π by 40π to get the length AB, so thus (0.4 * 40π)/(π) = 16π/π = 16
If you don't understand anything, feel free to ask!
