## DrPepperx3 Group Title geometry sucks >_< help ? :( medal! 3 months ago 3 months ago

1. DrPepperx3 Group Title

8. An airplane pilot over the Pacific sights an atoll of an angle of depression of 7 degrees. At this time, the horizontal distance from the airplane to the atoll is 3,729 meters. What is the height of the plane to the nearest meter? A. 458 meters B. 454 meters C. 3,667 meters D. 3,701 meters

2. DrPepperx3 Group Title

3. Musicman778 Group Title

I would say D but it's not a for sure answer

4. DrPepperx3 Group Title

can you explain to me how to work out the problem? cus im lost :c

5. Musicman778 Group Title

Well it says nearest meter, so just guesstimating it looks about 3701, D, but that's pretty much all I get.

6. ranga Group Title

What is the angle at the vertex on the right hand side of the triangle?

7. ranga Group Title

use "alternate interior angle" theorem.

8. DrPepperx3 Group Title

can you give an example?

9. ranga Group Title

|dw:1396650172181:dw|

10. ranga Group Title

Angle DAC = Angle ACB (alternate interior angle because AD and BC are parallel and the line or transversal AC cuts them.) Therefore angle C = 7 degrees. We want to find AB. We know BC to be 3,729 meters. What trig function connects AB and BC involving angle C?

11. DrPepperx3 Group Title

tan?

12. ranga Group Title

Yes. tan(C) = AB / BC AB = BC * tan(C) plug in the numbers and calculate AB.

13. DrPepperx3 Group Title

ok hold on c:

14. ranga Group Title

Make sure to set your calculator to degrees because 7 is in degrees and not radians.

15. DrPepperx3 Group Title

im using rad not deg right?

16. DrPepperx3 Group Title

oo ok!

17. ranga Group Title

18. DrPepperx3 Group Title

I got 0.701 ... I think I did something wrong .-.

19. ranga Group Title

As said before, set your calculator to DEGREES.

20. DrPepperx3 Group Title

its on degrees

21. DrPepperx3 Group Title

that's why im confused

22. DrPepperx3 Group Title

23. ranga Group Title

AB = BC * tan(C) = 3729 * tan(7) = ?

24. DrPepperx3 Group Title

b! 454 meters?

25. ranga Group Title

Try again.

26. DrPepperx3 Group Title

oops sorry I got over excited a lol I forgot to round

27. ranga Group Title