## rebecca1233 Group Title A polygon has an area of 100 square inches and one of its sides is 20 inches long. If a second similar polygon has an area of 36 square inches, what is the length of the corresponding side in the second polygon? 5 in 8 2/3 in 12 in 33 1/3 in one year ago one year ago

1. rebecca1233

@erdog82

2. erdog82

ok so, I believe you need to st up a proportion

3. rebecca1233

4. erdog82

ok I am trying to..

5. erdog82

so you know the areas of each polygon, right?

6. rebecca1233

36?

7. erdog82

and what?

8. rebecca1233

100?

9. erdog82

yes, good :)

10. rebecca1233

so what now ?

11. erdog82

|dw:1358803903084:dw|

12. erdog82

solve for x

13. erdog82

14. Mertsj

Not one of the choices.

15. rebecca1233

16. erdog82

did you see the drawing?

17. erdog82

?

18. rebecca1233

yes i saw it..

19. erdog82

try solving for x

20. rebecca1233

100x = 36*20?

21. erdog82

yup.

22. rebecca1233

720 = 100x

23. rebecca1233

then i divided and i got 7.2 but thats not one of the option choices..

24. erdog82

|dw:1358804299965:dw|

25. erdog82

oh yeah, what the heck?

26. Mertsj

Sorry but the ratio of the sides squared would be the ratio of the areas. And so the square root of the ratio of the areas would be the ratio of the sides.

27. erdog82

huh?

28. Mertsj

So if the ratio of the areas is 36/100, the ratio of the sides is 6/10

29. rebecca1233

7.2 is not an option for the answer.. answer options r .. 5 in. 8 2/3 in 12 in and 33 1/3 in

30. erdog82

@Mertsj you can help @rebecca1233 now... I guess you are better at this than I am

31. Mertsj

6/10=x/20 Solve that if you want the answer.

32. rebecca1233

so 6x= 10*20?

33. rebecca1233

help me ?

34. rebecca1233

hello @Mertsj

35. Mertsj

$\frac{6}{10}=\frac{x}{20}$

36. Mertsj

Can you solve that proportion?

37. rebecca1233

so 6 *20

38. rebecca1233

hen divie by 1 which gives u 12

39. rebecca1233

12 in is correct answer right?

40. Mertsj

yes

41. rebecca1233

i need help with another problem please

42. Mertsj