## anonymous one year ago A triangle has coordinates A (1, 5), B (-2, 1) and C (0, -4). What are the new coordinates if the triangle is dilated with a scale factor of 1/5 ?

1. anonymous

@pooja195

2. anonymous

Do I use the formula A' = A*f?

3. triciaal

|dw:1437619623775:dw|

4. anonymous

But do I use the formula that I mentioned?

5. triciaal

scale factor each length changes by factor to get the new length

6. triciaal

not sure what your formula represents

7. anonymous

A' stands for the new point, A stands for the original point, and f stands for scale factor

8. triciaal

with my approach the lengths are changing AB BC and AC start at one location then change to find new coordinates

9. anonymous

The new coordinates I got are A = (1/5 , 1) ; B = (-2/5 , 1/5) ; C = (0, -4/5)

10. anonymous

@pooja195

11. anonymous

Could u help me out?

12. anonymous

@SolomonZelman

13. anonymous

Are my new coordinates correct @SolomonZelman ?

14. anonymous

@Hero

15. anonymous

@Nnesha

16. nincompoop

There are different ways of dilation, but the most common if you are not asked to do it otherwise is to obtain the distance from the point of origin (0,0) to the coordinates one-by-one and factor it. Here is an example.|dw:1437621122694:dw|

17. nincompoop

|dw:1437621312440:dw|

18. nincompoop

|dw:1437621423014:dw|

19. nincompoop

|dw:1437621698705:dw|

20. anonymous

But this doesn't give me the coordinates...

21. nincompoop

it doesn't right away, but if you think about it, the distance formula is a derivation of the pythagorean theorem, which will allow you to work out the coordinates

22. nincompoop

I am providing you one of the ways to do this, and there will be other methods and they may even prove to be much easier depending on the situation. The point I was trying to drive home is the concept behind scaling factor that may either be a dilation or compression.

23. nincompoop

in other cases, the scaling or dilation may not be from the origin and you might be asked to do it at a certain point. |dw:1437621950818:dw|

24. anonymous

Are you familiar with this formula? A' = A*f

25. nincompoop

|dw:1437622134720:dw|

26. nincompoop

I do not use that formula, but I do know what that is. People write it differently, and all it boils down to is a multiplication or division from of a particular displacement.

27. anonymous

My school gave me that formula, and that's what I used to get the coordinates that I posted earlier

28. anonymous

Do u think they're correct? I'm pretty sure they are, but I'm still doubtful...

29. nincompoop

the concept has many applications which we do not have to memorize many formulas, we stick to basic ones. I will show you what I mean. |dw:1437622547410:dw|

30. anonymous

Sorry... still don't get it...

31. anonymous

What did u get for the new coordinates?

32. anonymous

@nincompoop

33. nincompoop

|dw:1437622635217:dw|

34. nincompoop

sorry, I am not going to answer your homework for you. If you really want the coordinates, you will have to understand the concept first and not focus so much on what formula you've been given. https://www.illustrativemathematics.org/content-standards/tasks/602

35. anonymous

Hehe, sorry but the method you're giving me is pretty confusing...

36. nincompoop

|dw:1437623473525:dw|

37. nincompoop

|dw:1437624194984:dw|

38. nincompoop

|dw:1437624415102:dw|

39. nincompoop

you can use the formula your school gave you all you want, but that limits you from understanding what is going on because they did not even explain how they got that formula in the first place. My concern before was that it was not emphasized that the formula you have was not a restricted dilation from the origin (0,0)

40. anonymous

Ok, I'll try to work on it.

41. anonymous

Thnx!!!

42. nincompoop

The beauty of what I am trying to show you is that it uses what other math you're familiar with and utilizing them to solve other problems.