SAT Mathematics Practice Test 6

The circumference, C, of a circle is $\mathit{C}=2\mathit{\pi }$, where r is the radius of the circle. For the given circle with a radius of 1, the circumference is $\mathit{C}=2\left(\mathit{\pi }\right)\left(1\right),$ or $\mathit{C}=2\mathit{\pi }.$ To find what fraction of the circumference the length of arc $\stackrel{\mathit{⌒}}{\mathit{A}\mathit{B}}$ is, divide the length of the arc by the circumference, which gives $\frac{\mathit{\pi }}{3}÷2\mathit{\pi }$.This division can be represented by $\frac{\mathit{\pi }}{3}\cdot \frac{1}{2\mathit{\pi }}=\frac{1}{6}$.The fraction $\frac{1}{6}$ can also be rewritten as $.166$ or $.167.$