Need some help with some physics problems. The counselor ruined my schedule and didnt give me trig so i technically shouldnt be in physics but they let me in. Anyway the problems are :

Find the dimensions for the quantity c4 in s=c3 cos(c4t) and t = T for time and L = length, s=L

L=c3 cos(c4T)

the c3 and c4's are c with the subscript number next to it

Also there is something about a Cartesian plane that I can't make much sense of:

The Cartesian coordinates of a point in the xy plane are x=-3.34m, y=-3.26m. Find the distance, r, from the poin of origin. Answer in units of m. Then calculate the angle Θ between the radius vector of the point and the positive x axis(measured coutnerclockwise from the positive x axis, within the limits of -180° and + 180°). Answer in units of °.