Question

I need help for my final exam. It is the IB Mathematics SL Paper Two for 2011. First problem. "The following diagram shows triangle ABC. AB = 7cm. BC = 9cm. And Angle ABC = 120 degrees. I need to find AC and the angle BAC.

Answer 1

use law of cosines AC = b AB=a BC = c
b^2 = a^2 +c^2 - 2ac*cos(120); b= 13.892
then use law of sines:
sin(ABC)/b = sin(BAC)/c; sin(120)/13.892 = x/9; x= 0.561040853
arcsin(x) = 34.13 degrees = m BAC

Answer 2

Although this is reasonably straightforward to visualize, could you attach an image? Scan or take a picture of it so we can see what the triangle looks like.

Answer 3

Lol. Or it could get answered lightning fast without that :)

Answer 4

thanks so much!

Answer 5

Give daniel a medal if you found his answer helpful!

Answer 6

(Just click the `Good Answer' button.)

Answer 7

where at?

Answer 8

To the right of his name, where you see the post above.