
William W. answered 10/30/19
Experienced Tutor and Retired Engineer
csc(θ) = 1/sin(θ) and sin(θ) = opposite/hypotenuse (or O/H) so that means csc(θ) = H/O so since csc(θ) = 13/5 then that means the hypotenuse = 13 and the opposite = 5.
So the triangle looks like this:
To determine sin(2θ), you will need to use the double angle equations:
sin(2θ) = 2sin(θ)cos(θ) in the triangle above, we can calculate the other side of the triangle using the Pythagorean Theorem and it turns out to be 12. So the sin(θ) = 5/13 and the cos(θ) = 12/13. So sin(2θ) = (2)(5/13)(12/13) = 120/169