To start with we have to write down what we know. pi=3.14, r=9, arc length is 1. x is the angle we are trying to find. Saying that the radius is 9
There is an equation that states that the arc length is equal to x/360 (the fraction of the circle) multiplied by the circumference or 2 times pi times the radius. where * means multiply. Simplify Take the 28.26 over to the other side of the equation, where it then it divides the 1. This becomes: Then the 360 is brought over to the other side and multiplies the 0.035: And finally simplify the whole equation and we get our answer.