## superloz 2 years ago help http://prntscr.com/1l4tko http://prntscr.com/1l4ttt

1. superloz

how to find the second one?

2. OpenSessame

The diagonals are in the middle of the triangle so its basically it is breaking it up in 4 equal peices.

3. superloz

pok

4. superloz

ok

5. superloz

then

6. OpenSessame

So if you are trying to find ac it would what half of it twice.

7. OpenSessame

so (x+4)(x+4)

8. superloz

simplify?

9. OpenSessame

Since you have the sum of the length of the diaganols you have to make an equation equal to 20.

10. OpenSessame

(2x-3)(2x-3)+(x+4)(x+4)=20

11. OpenSessame

You have to solve for x before moving on

12. superloz

13. OpenSessame

Uh one sec still solving!

14. OpenSessame

Plug it in to check!

15. OpenSessame

I dont think thats it?

16. superloz

idk

17. superloz

i solve this for x (2x-3)(2x-3)+(x+4)(x+4)=20

18. OpenSessame

You have to do the quadratic eqaution...

19. superloz

20. OpenSessame

did you get 5x^2-4x+25=20 when you simplified?

21. superloz

yep

22. OpenSessame

Okay you need quad to find x give me a minute and ill do it...

23. superloz

ok

24. OpenSessame

Its an imaginary number...

25. OpenSessame

Assuming the rhombus is ABCD and E is the intersection of the diagonals, then we know the diagonals perpendicularly bisect each other, so AE is half of one diagonal and BE is half the other diagonal. That allows us to solve for x: (x+4) + (2x-3) = 20/2 3x + 1 = 10 3x = 9 x = 3 and since BE = 2x - 3 = 3 is half of BD, BD = 2*3 = 6 (answer C).

26. OpenSessame

Figured out the better way to solve it lol

27. superloz

thank you

28. OpenSessame

DO you understand how i got there?

29. superloz

so BE is half and BD is the other half?

30. superloz

each is 3?

31. OpenSessame

Wait!!! i messed up lol you plug the three in x+4 and multiply it by 2 because you are finding ac

32. OpenSessame

For some reason i thought it was the other one. But it will be 14 in that case.

33. superloz

thanks