Hello Tialah,
(i) Plot the coordinate (8,-6), which would land in the fourth quadrant
(ii)
a) Draw a line from the origin to the coordinate.
b) Then draw a line from the coordinate perpendicularly back to the nearest x-axis
c) You should now have a right triangle formed
iii) In this right triangle, label the angle nearest the origin with Θ.
iv) Label the horizontal side of the triangle with 8 and the vertical side with -6.
v) By Pythagorean, find the value of the hypotenuse, which will be 10.
vi) From SOHCAHTOA, sin(Θ) = -6 / 10 = -3 / 5.
I hope the above helps, and thank you for the question.
Michael Ehlers