AcidRa1n 3 years ago Drawing.

1. AcidRa1n

|dw:1338436072983:dw|

2. AcidRa1n

AB has 150 degrees. Whats the area of AOB?

3. ChristineToTheRescue

...which one is o...i only see A, B, &C...

4. AcidRa1n

sorry !! O is the center

5. AcidRa1n

|dw:1338436524089:dw|

6. ChristineToTheRescue

okay... soo hold on

7. ChristineToTheRescue

|dw:1338436260093:dw|

8. ChristineToTheRescue

...but angle a-b....

9. ChristineToTheRescue

|dw:1338436293890:dw| would the angel be something like that?...

10. ChristineToTheRescue

11. AcidRa1n

|dw:1338436594595:dw|

12. AcidRa1n

awh ok :(

13. ChristineToTheRescue

very sorry.

14. AcidRa1n

Hey Satellite, can you help me?

15. satellite73

|dw:1338436556319:dw| this area?

16. AcidRa1n

Yeah!

17. satellite73

so total area if the radius is 4 is $$16\pi$$ and you are missing a piece. the total number of degrees is 360 so you are missing a $$\frac{150}{360}$$ of the circle leaving you with $$\frac{210}{360}=\frac{7}{12}$$ of the circle

18. satellite73

your last job is to multiply $$16\pi\times \frac{7}{12}$$

19. AcidRa1n

Ah I dont understand :( I hate math so much..

20. satellite73

ok lets go slow

21. satellite73

radius of the circle is 4 right? i mean from the picture

22. AcidRa1n

When my teacher did it in class, it was much faster and more simple I just forget what he did..

23. AcidRa1n

yeah

24. satellite73

and the area of a circle with radius $$r$$ is $$\pi r^2$$ in this case $$\pi\times 4^2=16\pi$$ so if a piece was not missing, the whole area would be $$16\pi$$

25. AcidRa1n

4 times 150 = 600.. 600 / 360 = 120 degrees?

26. satellite73

so the only question is, what portion of the circle is left

27. satellite73

hold on degrees is a measure of an angle. area measures something entirely different

28. AcidRa1n

Oh yeah im sorry

29. AcidRa1n

I was doing length

30. satellite73

the whole circle contains 360 degrees and you are missing 150 of them so you have left $$360-150=210$$ degrees

31. AcidRa1n

It's Area im trying to find sorry

32. satellite73

therefore you have what portion of the whole circle left shaded? it is $\frac{210}{360}=\frac{7}{12}$ i.e you have seven twelfth of the circle left shaded

33. satellite73

the entire circle has area $$16\pi$$ and you have $$\frac{7}{12}$$ of it left, so your area is $16\pi\times \frac{7}{12}=\frac{28\pi}{3}$

34. AcidRa1n

You know what excuse my language. flutter math. All you need in life is Add Subtract Multiply and Divide. No, i'm not going to be a engineer, so needing all of this is out of the question. This kind of stuff does not work well in my brain. I feel it's unfair that us less fortunate people have to pay the price. Bad grades and getting spanked. No matter what I do I just dont get this stuff, I try really hard. I've been studying for this final exam for about 5 hours now, and I probably learned nothing. This is a load of crap and it's not fair. Sorry for wasting you time with this problem i'll be going to sleep now do to its 12:15 am here. Thanks.