## Setsuna-Yuregeshi one year ago What is a similarity statement and how do I write one? I learned about them in geometry the other day, but i still don't understand them.....

1. phi

a good example of "similar" in geometry is a square. two squares of different sizes are similar (they have the same shape, and their sides form identical angles)

2. phi

if two shapes are similar, then if you change the size you can make them look identical.

3. anonymous

hes right

4. Setsuna-Yuregeshi

OOH, I see.. What's a similarity statement? How do you write one?

5. anonymous

stating something like they have the same angles

6. phi

similar is useful when you have triangles. Here is an example: |dw:1436992086041:dw|

7. phi

the two triangles have the same shape, but different sizes. but say you know the height of the person, and measure his shadow then you measure the length of the tree's shadow. because the triangles are similar , we can figure out how high the tree is!

8. anonymous

@phi how do you bring up your engagement stat

9. anonymous

same question for teamwork

10. phi

the "similarity statement" could be written: person's height: his shadow :: tree's height: tree shadow or using fractions $\frac{person\ height}{his \ shadow} = \frac{tree\ height}{its \ shadow}$

11. phi

though in geometry, we usually use letters to name the sides of a triangle.

12. phi

Does this sound like what you were being taught?

13. Setsuna-Yuregeshi

Yeah, it's just I didn't get it then.....

14. Setsuna-Yuregeshi

Sorry, but @phi, what is a similarity statement?

15. phi

a similarity statement tells you which sides "go with" which side. for example, suppose we have these two triangles |dw:1436992841773:dw|

16. phi

the angle at A "matches" the angle at Y B with Z C with X we could write ABC is similar to YZX (in fact people would usually label the 2nd triangle so it reads XYZ, to make it clearer)

17. phi

I think they use ~ instead of = so you would write ABC ~ YZX and that is short to say: angle A matches angle Y angle B matches angle Z angle C matches angle X it also says: side AB is similar to side YZ (the side from angle A to angle B) matches the side from Y to Z and side BC ~ side ZX

18. phi

Does that sound familiar?

19. Setsuna-Yuregeshi

Sorry, I havee to go, but I will come back later.

20. Setsuna-Yuregeshi

@phi, Thank you. On my homework though sometimes I didn't see them corresponding in the choices. Like how you had ABC similar to YZX..... Or maybe I just didn't see it right...

21. phi

Post a specific question and choices, and maybe we can make sense of it.