## anonymous one year ago What is the difference between rotation about the origin and rotation about the center of the figure?

1. LynFran

rotation about the origin is the point (0,0) and rotation about the center is any point(x,y)

2. LynFran

for the origin x=0 & y-=0

3. LynFran

for the center x can equal any value also y...example (2,9) x=2 y=9

4. anonymous

So this would be about the center?

5. anonymous

@LynFran

6. LynFran

ok what exactly is the question i find that for the point H with H' and F with F' $\left[\begin{matrix}1 & 0 \\ 0 & -1\end{matrix}\right]$ ...what i would also like to know if the topic is matrices

7. anonymous

Here is the full question: Carlos performed a transformation on trapezoid EFGH to create E'F'G'H', as shown in the figure below: [insert picture i posted before] What transformation did Carlos perform to create E'F'G'H'? and the answer choices are: A. Rotation of 90 degrees counterclockwise about the origin B. Rotation of 90 degrees counterclockwise about the center of the figure C. Rotation of 90 degrees clockwise about the origin D. Rotation of 90 degrees clockwise about the center of the figure

8. anonymous

@LynFran So I assume that it would be 90 degrees clockwise, correct? But I'm not sure if it is about the origin or about the center.

9. Loser66

|dw:1435026349286:dw|

10. Loser66

to go from F to F' , you need go on which direction to get 90 degree? |dw:1435026460507:dw|

11. anonymous

counter clockwise

12. Loser66

yup, but you got what it means, right?

13. anonymous

Yeah I understand that part now. I just dont understand what it is rotating "about"

14. Loser66

you have 90 degree, right? and 2 options: about origin and about center of the figure, right? if about origin, that is : all vertices of the original one perpendicular with the corresponding vertices of the new one through origin. Like what I draw, FO $$\perp$$ F'O

15. Loser66

if you link AO and A'O, you can see they form a 90 degree also.

16. Loser66

If about center of the figure, first off, you have to find that center, then, link the vertices like what you did with O. Dat sit

17. anonymous

So then it would be about the center of the figure?

18. Loser66

|dw:1435026925440:dw|

19. Loser66

20. anonymous

Oh I think I understand

21. anonymous

Thank you

22. Loser66

ok

23. anonymous

Wait a second I just entered that answer (A) and it said it was wrong

24. Loser66
25. Loser66

http://www.onlinemathlearning.com/rotation-transformation.htm I don't know why it said wrong. :(

26. anonymous

basically if you turn it around the origin the position of the shape and position of the shape on the grid would change but if you turn it on its center it just changes the position of the shape