gabbyalicorn one year ago What is the approximate perimeter of the figure? A. 7.85 in. B. 12.9 in. C. 17.9 in. D. 31.4 in.

1. gabbyalicorn

2. geerky42

This looks like 1/4 of circle, right?

3. gabbyalicorn

right

4. geerky42

yeah, so that arc would be 1/4 the circumference. Agree?

5. gabbyalicorn

yeppers

6. geerky42

And you also have two radii |dw:1433134466763:dw|

7. geerky42

You know what's total length of these thick lines?

8. gabbyalicorn

90 is the length?

9. geerky42

|dw:1433134560634:dw|

10. geerky42

That's 5+5

11. gabbyalicorn

oh 10

12. geerky42

Yep, easy part. Now arc. Again it's 1/4 of circumference, so what is it?

13. gabbyalicorn

is there anyway to convert 1/4 into like a number?

14. geerky42

You can just divide it by 4?

15. gabbyalicorn

2.5

16. geerky42

Or you can use calculator to find 1/4 $$1\div4$$

17. geerky42

It's not 2.5 btw

18. gabbyalicorn

0.25

19. geerky42

yeah, so you multiply circumference by 0.25

20. gabbyalicorn

but i thought the circumference is 0.25

21. geerky42

no no. it's just that you find whole circumference, THEN you multiply it by 0.25

22. gabbyalicorn

so, 4 x 0.25?

23. gabbyalicorn

no that wouldn't make sense

24. geerky42

What is circumference? $$C = 2\pi r$$, right?

25. geerky42

Find that then you multiply it by 0.25

26. geerky42

$$\dfrac{C}{4}$$ or $$0.25C$$

27. gabbyalicorn

oh so 2 x 3.14 = 6.28 x 0.25 = 1.57

28. geerky42

you forgot radius. From picture, radius is 5, right?

29. gabbyalicorn

oh oops so then it would be 7.85

30. gabbyalicorn

A :D !!!

31. geerky42

Not quite

32. geerky42

That is correct, but you forgot to add two radii

33. geerky42

34. gabbyalicorn

wait 2

35. gabbyalicorn

so 10

36. gabbyalicorn

37. geerky42

|dw:1433135159595:dw|

38. gabbyalicorn

-3- i thought we just did that...

39. geerky42

yeah we did. Now we add them together.

40. geerky42

|dw:1433135231571:dw|

41. gabbyalicorn

17.85

42. geerky42

|dw:1433135261928:dw|

43. geerky42

Yep.

44. gabbyalicorn

:D thank you so much! I know i cant really show it through typing but I REALLY APPRECIATE YOU HELPING ME! :D

45. geerky42

No problem!

46. gabbyalicorn

im looking at the answer but why does a havethe 1 not there?

47. gabbyalicorn

its c because we round right?

48. gabbyalicorn

@geerky42

49. gabbyalicorn

wait but it doesnt say to round

50. gabbyalicorn

okay well im going with A