how do I solve?

Question

sin (3ɵ + ð/18) = 1

Answer 1

I will assume 3ɵ + ð/18 means 3ɵ + pi/18

look at your sine curve.
the sine is 1 at 90º or pi/2

so 3ɵ + pi/18 = pi/2

multiply 3ɵ + pi/18 = pi/2 by 18

54ɵ + pi = 9pi

ɵ = 8pi/54 = 4pi/27