enter image description here

Alright, so i've been trying to tackle this problem. The answer to this problem is 40 degrees (3). Now i'm trying to figure out how.

I decided to start with finding the area of the whole circle which is $9\pi$ cm$^2$ since the radius is 3 cm

but I do not how to proceed from there. Any ideas or hints?

  • $\begingroup$ There is a formula that allows you to compute the shaded sector from the angle LOM and the radius of the circle. $\endgroup$ – Diego Jul 20 '16 at 5:13

The area of the shaded sector is $\frac{\theta}2 r^2$, where $\theta = \angle LOM$. Hence, $\theta = 4\pi/9$, so $\angle NOM = 5\pi/9$.

Now $\triangle NOM$ is isosceles at $O$, so $2\angle N = \pi - \angle NOM = 4\pi/9$, hence $\angle N = 2\pi/9 = 40^{\circ}$.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.