## anonymous one year ago HELP!!! The surface area of two similar rectangular prisms are 361m2 and 441m2. What is the scale factor of the larger prism to the smaller prism? A.) 361/441 B.) 19/21 C.) 21/19 D.) 19/11

1. anonymous

2. anonymous

@Nnesha

3. anonymous

@nincompoop

4. ganeshie8

Hint : If areas of similar figures are in ratio $$\dfrac{a}{b}$$, then the lengths(scale factors) will be in ratio $$\dfrac{\sqrt{a}}{\sqrt{b}}$$

5. anonymous

so i just take each answer choice and do that to them??

6. anonymous

i'm still not understanding

7. ganeshie8

Yes, first setup the ratio of areas

8. anonymous

is it 19/21

9. ganeshie8

careful, they want larger prism on top

10. ganeshie8

ratio of areas = $$\dfrac{441}{361}$$

11. anonymous

so its C?

12. ganeshie8

so, ratio of scalefactors = $$\dfrac{\sqrt{441}}{\sqrt{361}}=?$$

13. anonymous

21/19

14. ganeshie8

Yep!

15. anonymous

i have another question if thats ok

16. ganeshie8

17. anonymous

The two cones are similar. Find the surface area of the larger cone. Round your answer to the nearest hundredth. A. 810.28 B. 847.80 C. 868.30 D. 886.25

18. anonymous

19. anonymous

@ganeshie8

20. anonymous

S=π×11.12+π×11.1×13.8 is the formula, solve that and u will get the answer

21. anonymous

I got 516..../

22. anonymous

that's not right

23. anonymous

hmm let me solve and see what i get

24. anonymous

ok

25. anonymous

i am sorry the same question is on open study and I checked the formula I am so sorry I was not able to help

26. anonymous

27. anonymous

its ok. @ganeshie8 can you help

28. anonymous

thnx