1. anonymous

are these answers correct? the first one i got 282.6m^2 the second one i got 175.84in^2

2. amistre64

if you can cut the cone up its lengthand make into part of a circle, the surface area is easy to get :) maybe even easy if I think about it some

3. amistre64

is the 10 inches the length up the side of the cone or the height?

4. anonymous

length

5. anonymous

its actually slant height

6. amistre64

then that 10 inch length is the radius of a larger circle, find its circumference" 2pi10 20pi is its curcumference the small base circle is the length of the circumference that you want to find an area for 2pi4 = 8pi make sense?

7. anonymous

kinda

8. anonymous

$s =\pi \times r ^{2}+\pi \times r \times l$ is the formula i need to use

9. amistre64

length of an arc = theta(r) 8pi = theta(10) theta = 8pi/10 = 4pi/5 area of sector = theta r^2/2 (4pi/5)(10)(10)/2 200/5 = 40pi fpr the surface area of the cone, do we include that base in this or not?

10. amistre64

40pi + 16pi = 56pi if I did it right :)

11. anonymous

ok

12. anonymous

would = 175.84in^2

13. amistre64

175.92 is what I get... is that close enough?

14. amistre64

175.84 if you use (3.14)

15. anonymous

yea

16. anonymous

how would i find the surface area of this one

17. amistre64

if im doing it right, I get 85pi

18. anonymous

would i use half the diameter?

19. amistre64

if you dont have answers to check against, I would suggest gettting a second opinion :) but yes, radius is half the diameter

20. anonymous

$s =\pi \times 5^{2}+\pi \times 5 \times 12$

21. amistre64

i got 25pi + 60pi too :)

22. amistre64

im glad the formula works :)

23. anonymous

witch would = 266.9ft^2

24. anonymous

25. amistre64

i could try.... getting kinda deer in the headlights feeling....must.....carry.........on. . . . . . . ok

26. anonymous

find the surface area of the regular pyramid

27. amistre64

#31 3cm is pointing to what?

28. anonymous

3cm is height i believe

29. amistre64

is it face height or pyramid height?

30. anonymous

the formula for this on is S=B+1/2Pl

31. anonymous

looks like pyramid hight

32. amistre64

pyramid height would have a dotted line stricking down the middle of it..... i think its face height.

33. anonymous

so do i

34. amistre64

4cm^2 + 12 cm^2 = 16 cm^2 for #31

35. amistre64

#32...all I see is a 7 and not much else for details...

36. anonymous

thats all there is

37. amistre64

is that all sides are 7? like an equalateral triangle?

38. anonymous

yea

39. amistre64

then I would do: 4 times (1/2)(49)sin(60) 84.87 m^2

40. amistre64

if you have a side-angle-side, the area can be determined by: (side)(side)(sin(angle))/2 and there are 4 sides so I timesed it by 4 :)

41. amistre64

(side)sin(a) = height, and the other side = base

42. anonymous

ok

43. amistre64

and for the last one its just like the first except with decimals..

44. amistre64

(9.2)^2 + 4(9.2)(13)/2

45. amistre64

84.64 + 239.2 = 323.84

46. anonymous

okay thank you so much

47. amistre64

youre welcome :)