Answer:
126.9° and 323.°1
Explanation:
I'll use x instead of theta and you can replace it by theta
5 sin x + 3 = 0
5 sin x = - 3
Sin x = - 3/5
Key angle = sin¯¹ 3/5 = 36.8698
Sin negative, so we use the third and fourth quadrants
X = 90+36.8698, 360-36.8698
X = 126.8698, 323.1302
Theta = 126.9°, 323.°1