posted by Ma .
if side x=15 and side y=8 what is sin of the angle.
Is it a right triangle? Is side x the hypotenuse?
A figure needs to go with your question.
If the angle in question is measured from the x axis, and the angle is defined by the x axis and a line from the origin to (x,y), then the angle is arctan 8/15 and the sine is 8/sqrt(64 + 225)