## Flapdragon 3 years ago I need some help finding the surface area of this figure...

1. Flapdragon

2. UnkleRhaukus

a little circle a big circle and an trapezium

3. UnkleRhaukus

|dw:1333783298213:dw| It is not a trapezium but a difference of sectors

4. UnkleRhaukus

|dw:1333783389861:dw|

5. UnkleRhaukus

do you mind if i work in radians (or do you prefer degrees) radians will be simpler

6. Flapdragon

7. UnkleRhaukus

how do we find the extra height to the nonexistant apex of the cone

8. fl3x1

Do you know the final answer so i can confirm? is it 388.355? if yes then ill explain it

9. UnkleRhaukus

|dw:1333784950944:dw|

10. Flapdragon

I don't really know what the final answer is (or how to find the extra height). :c

11. fl3x1

|dw:1333785068455:dw| i just added the surface areas of these two figures..

12. fl3x1

suface area of cone + surface area of circle

13. UnkleRhaukus

but the bit that goes round the middle is not a sector , it is a difference of sectors

14. fl3x1

im not sure its right though

15. Flapdragon

Anyway, thank you both for helping! I'm...still not entirely sure how to do this problem, but I have a couple of ideas now, so...