Question 873672
*[illustration triangle.pdf]

The side of the triangle has length 8, since the y-coordinate of the point B is -8.
The base of the triangle has length 3, since the x-coordinate of the point B is 3.
The hypotenuse of this triangle, from the Pythagorean Theorem, is:
{{{sqrt(8^2+3^2) = sqrt(73)}}}
The sine of the angle is BC/AB = {{{3/sqrt(73)}}}
This is the same as answer (A) if you divide through by {{{sqrt(73)}}}