anonymous 5 years ago find the surface area of the space figure. 28 ft by 36 ft.

1. anonymous

its a cylinder if that helps

2. anonymous

plz help!

3. anonymous

Surface Area = Areas of top and bottom +Area of the side Surface Area = 2(Area of top) + (perimeter of top)* height Surface Area = 2(pi r 2) + (2 pi r)* h

4. anonymous

a cylinder is made up of 3 parts: 2 circles are each end, and a rectangle wrapped around the circles for the main part

5. anonymous

it is a 3dimenton figer

6. anonymous

Surface Area of a Cylinder = 2 pi r 2 + 2 pi r h

7. anonymous

ok, but why is that the case? because there are 2 circles (for the 2 * pi*r^2), then a rectangle which constitutes the middle, the rectangle has height=h, and the width of the rectangle equals the circumference of the circle, which is 2*pi*r

8. anonymous

so the area of the two circles is: 2* (pi*r^2) area of the rectangle is: h * width, where width = 2*pi*r, so -> h*(2*pi*r)

9. anonymous

(h is the height of the cylinder, r is the radius of the top)

10. anonymous

so as glenn pointed out: Surface Area of a Cylinder = 2 pi r 2 + 2 pi r h

11. anonymous

which is area of both circles plus the area of the rectangle

12. anonymous

yes

13. anonymous

hold on wrong chat

14. anonymous

that i am get ing i have not did this in a long time

15. anonymous

Surface Area = 2(pi r 2) + (2 pi r)* h

16. anonymous

yes..

17. anonymous

ok?

18. anonymous

sorry was gone

19. anonymous

dk?

20. anonymous

help?

21. anonymous

yes with what

22. anonymous

???

23. anonymous

same question

24. anonymous

Surface Area = 2(pi r 2) + (2 pi r)* h