SAT Question 9f9112ab: Circles answer and explanation with Desmos solution

The measure of an angle in radians is equal to the measure of the angle in degrees multiplied by $\frac{\pi }{180}$. It’s given that the measure of angle $L$ is $60$ degrees. Multiplying $60$ by $\frac{\pi }{180}$ yields $\frac{60\pi }{180}$, or $\frac{\pi }{3}$. It’s also given that the measure of angle $L$ is $\frac{\pi }{n}$ radians, so $\frac{\pi }{n}=\frac{\pi }{3}$. Dividing both sides of this equation by $\pi$ yields $\frac{1}{n}=\frac{1}{3}$. Taking the reciprocal of both sides of this equation yields $\frac{n}{1}=\frac{3}{1}$, or $n=3$. Therefore, the value of $n$ is $3$.