In the $xy$-plane above, points $A, B, C, \text{ and }D$ lie on the circle with center $O$. The degree measures of angles $AOC$ and $BOD$ are each $35\degree$. What is the radian measure of angle $AOB$ ?

Summary Submit Skip Question

Since half of a circle is $180 \degree$, $m\angle AOB$ must be $110\degree$ .

Converting this into radians:

$$110 \degree \cdot \frac{\pi \text{ rad}}{180\degree}$$ $$= \boxed{\frac{11\pi}{18}} \text{ radians}$$