A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

anonymous

  • one year ago

Circle B has a center of (−1, 5) and a radius of 4. Circle D has a center of (7, 4) and a radius of 2. Prove that the two circles are similar.

  • This Question is Closed
  1. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    @Jack1 please help

  2. Jack1
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    similar how...? all circles are similar...? circle d is just like 1/2 the size of circle b, sáll

  3. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    I know i'm just confused on this question!:/

  4. Jack1
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    i dont really understand... with triangles they can have different shapes so it makes sense when trying to prove they're similar... but all circles are the exact same shape... i dont get it either, sorry ;(

  5. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    thanks anyway but do you know anyone who can?

  6. Jack1
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    @ganeshie8 lil help if u have a sec man, i'm lost on this one dude...?

  7. Jack1
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    or @dan815 ? u got a sec? how are circles "similar"?

  8. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    thanks for trying to help man!:)

  9. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    @ganeshie8 please help

  10. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    @dan815 could you help me on this question please?

  11. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    anyone please help!

  12. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    @phi

  13. Jack1
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    @IrishBoy123 ur pretty cluey, du u understand this Q man?

  14. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    @phi i really need help with this question!

  15. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 4

    similar means the objects have the same shape (but possible different sizes) if we take two objects and "scale" one to be the same size as the other, and then show they can be laid on top of the other, that would show they are similar.

  16. IrishBoy123
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    https://www.illustrativemathematics.org/content-standards/tasks/1368 is any of this familiar to you you move one circle onto the other and shrink or enlarge it to prove they are similar

  17. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    okay

  18. Jack1
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    circles are always similar tho, right...?

  19. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    yes

  20. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 4

    I would start with Circle B has a center of (−1, 5) and a radius of 4 and translate (that means slide it) so its center is at (0,0) (its shape will not change) then shrink it by 2: its radius will go from 4 down to 2

  21. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    okay then what?

  22. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 4

    next, Circle D has a center of (7, 4) and a radius of 2. slide D so its center is at (0,0) its radius is 2, and it will lie directly on top of the other circle (which we moved to (0,0) and shrank to radius = 2) this shows the two shapes are identical. Identical shapes mean the shapes are similar.

  23. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    do I have to determine a rule?

  24. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 4

    a rule for what ? there is the procedure to translate the circles and shrink (or expand) them so they lie on top of each other. there is the "rule" that all circles are similar...

  25. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    oh okay sorry.

  26. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    do i just picture this in mind or do i draw it?

  27. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    or not at all?

  28. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 4

    nobody else can read your mind, so you have to write down something. I would sketch (graph) the original circles then draw an arrow to show they are translated to the (0,0) origin and write down "translate the center of the circle to (0,0)" then show the two circles centered at the origin then shrink the big circle by 2 (multiply its radius by 1/2) and write "use dilation to change the size from radius 4 to radius 2" then show a picture with both circles on top of each other, and write "both circles lie on top of each other, and this shows they have the same shape" "same shape means they are similar"

  29. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    okay but that's not what it asks in my question! How about the other written part?

  30. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 4

    they ask, "Prove that the two circles are similar." A proof would be doing all the things I just posted.

  31. Jack1
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    i;m still not understanding either @phi couldn't we just right "they're circles : QED"?

  32. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    but I can't take a picture of everything i just drew and put it in my question!

  33. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 4

    then just write the words that explain what you would do.

  34. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    I'm still really confused

  35. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    so i just put what you just wrote but in my own words?

  36. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 4

    yes. Try to use your own words.

  37. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    so this part? would sketch (graph) the original circles then draw an arrow to show they are translated to the (0,0) origin and write down "translate the center of the circle to (0,0)" then show the two circles centered at the origin then shrink the big circle by 2 (multiply its radius by 1/2) and write "use dilation to change the size from radius 4 to radius 2" then show a picture with both circles on top of each other, and write "both circles lie on top of each other, and this shows they have the same shape" "same shape means they are similar"

  38. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    ?

  39. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 4

    @Jack1 I think this is some goofy "common core" idea. In Euclidean geometry I think it is assumed circles are similar

  40. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 4

    Yes Josh, but try to rewrite it using your own words.

  41. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    oh okay thank you!:)

  42. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    it says prove so that would be my proof?

  43. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 4

    yes

  44. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    oh okay double checking! thanks again!:)

  45. IrishBoy123
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    @phi awesome work!

  46. Not the answer you are looking for?
    Search for more explanations.

    • Attachments:

Ask your own question

Sign Up
Find more explanations on OpenStudy
Privacy Policy

Your question is ready. Sign up for free to start getting answers.

spraguer (Moderator)
5 → View Detailed Profile

is replying to Can someone tell me what button the professor is hitting...

23

  • Teamwork 19 Teammate
  • Problem Solving 19 Hero
  • You have blocked this person.
  • ✔ You're a fan Checking fan status...

Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.

This is the testimonial you wrote.
You haven't written a testimonial for Owlfred.