## anonymous one year ago The angle of depression from the top of the tree to the tip of the shadow is 25°. Find the height of the tree to the nearest tenth. a. 16.8 feet b. 18.2 feet c. 23.4 feet d. 39.7 feet

1. anonymous

2. anonymous

3. freckles

|dw:1437363564659:dw| just use the tangent ratio

4. freckles

though that is the angle of elevation not angle of depression

5. anonymous

how do i solve it what equation

6. freckles

alpha is the angle of elevation which is 25 deg recall tan is opp divided by adjacent

7. anonymous

8. freckles

since it does say angle of depression I wonder if it is talking about this angle being 25 deg|dw:1437363976910:dw|

9. freckles

|dw:1437364051842:dw| but that still makes that one angle 25 deg

10. anonymous

so what do i divide by

11. freckles

so it didn't matter

12. freckles

you just do $\tan(25)=\frac{\text{ opp side of the angle with measurement } 25 \deg}{ \text{ adj side of the angle with measurement } 25 \deg}$

13. freckles

the opp side is what I called h in the picture

14. freckles

anyways let me know if you need further help

15. anonymous

i dont know what the measurement is

16. freckles

which one?

17. anonymous

h

18. freckles

h is what you are solving for

19. freckles

remember h is the height of the tree

20. freckles

that is what you are solving the equation for

21. freckles

you are given the adjacent side the side that touches the angle (and no adjacent side is not the hyp)

22. freckles

|dw:1437364301549:dw|

23. anonymous

so what next

24. freckles

pluggin those numbers into equation I gave

25. freckles

then just solving it for h and then bingo you are done

26. triciaal

use the equation given above by @freckles

27. freckles

$\tan(25)=\frac{\text{ opp side of the angle with measurement } 25 \deg}{ \text{ adj side of the angle with measurement } 25 \deg} \\ \tan(25)=\frac{h}{36}$ notice I just put what I called the opp where I said opp side notice I just put what I called the adjacent measurement for the adjacent side can you solve the equation?

28. triciaal

|dw:1437364501206:dw|

29. triciaal

did you get A?

30. anonymous

i didnt get anything yet

31. anonymous

what i got 900. i know that isnt right

32. freckles

ok @GEOMETRYHELP10011 do you know how to do tan(25) in your calculator ?

33. anonymous

no

34. freckles

oh that could be a big problem for solving the equation

35. freckles

because it does require you to type tan(25) in your calculator

36. freckles

you should see a button with tan on it

37. freckles

you should see it next to things like sin and cos

38. freckles

if you can't find them tell me the name of your calculator and I can tell you where it is

39. anonymous

i got at 16.7

40. freckles

ok that's great

41. freckles

that is what I and @triciaal also got

42. freckles

well 16.8

43. triciaal

to round to the nearest tenth solve to 2 decimals you have 16.78 then look at the 2nd place if 5 or more add 1 to the digit before 8 is more than 5 so you round to 16.8 if the 2nd digit was less than 5 then you would drop it and round to 16.7