tan (theta) = 14/5
theta = tan¯¹(14/5) = 70.3° + 180°k where k is an integer.
Since theta is in quadrant III, the angle should be between 180° and 270°.
Let k = 1. Then 70.3° + 180°k = 70.3° + (180° × 1) = 250.3°.
Now the angle is in quadrant III, so we can proceed to evaluate its sine value.
sin(250.3°) = –0.9415
