Question

write the complex number in trigonometric form with the angle in the interval (0,360) 3sqrt3 +3i

Answer 1

Do you know what this question is asking for @ktg1006?

Answer 2

A complex number in polar form looks like the following

\[ \large z =r\text{cis}(\phi) = r (\cos \phi + i \sin \phi)\]
So in order to establish that form, you need an r, which is an argument and an representative angle \(\phi\). Mention to me if you don't know how to find them.