I have a triangle with the points A( 5,-2) B(0,0) and C(4,2) . I have to rotate the triangle so that the line BA sits on the positive x axis. I am stuck, how to work out the values for sin, cos and tan?
I have worked out the lengths of those lines BA = sqroot, AC = sqroot and BC = sqroot. After that I have no idea where to start, any help is appreciated.
Feb 5th 2010, 03:46 AM
use the sine and cosine laws to find two angles, then draw line AB on the x-axis, since you know how long it is, and then lines AC and BC off of it having calculated the right angles
a^2 = b^2 + c^2 - 2bcCosA
a/SinA = b/SinB = c/SinC
Feb 5th 2010, 04:21 AM
Thanks, I think I get it. It says though I don't need the angle but I should express the rotation as an equation. Do you know about that?