## anonymous 5 years ago How would you find the area of the shaded regions in these two pictures

1. anonymous

2. anonymous

First one is $\pi r ^{2}$ Second one is $sr \theta$ Change your theta to radians for the second one.

3. anonymous

so the first on would be 70.84 in^2?

4. anonymous

The equation for the first one should look like $\pi(4.75)^{2}$

5. anonymous

So sqaure 4.75 and then multiply it by $\pi$

6. anonymous

okay that makes since for the first one

7. anonymous

on the second one im still not sure what you ment

8. anonymous

Ah sorry I wrote that wrong it is $S = r \theta$ This means the area of the shaded region is equal to the radius multiplied by the angle. Change the angle to radians by multiplying it by $\pi/180$

9. anonymous

so pi/180=.0174

10. anonymous

What math are you in?

11. anonymous

geometry

12. anonymous

Ah no wonder. Lol. I'm trying to make you use trig methods. Here, Multiply the 80 or whatever that is on the outside of that shaded region by $\pi/180$ Then you simply that to get $8\pi/18$ Which can be simplified further to $4\pi/9$ Now you multiply, I beliebe it says 8.9?, by that using 3.14 for pi. Itd look like this $8.9(4\pi/9)$

13. anonymous

14. anonymous

okay.. thank you

15. anonymous

Sorry if that's confusing :S It's trigonometry.

16. anonymous

ios okay