The Cartesian coordinates of a point are (x, y).
'x' and 'y'are both distances.
The polar coordinates of the same point are (R, A).
'R' is a distance. 'A' is an angle.
How to find 'R' and 'A' when you know 'x' and 'y' :
R = distance of the point from the origin = square root of (x² + y²)
A = angle clockwise from the x-axis to the point = angle whose tangent is (y/x)
=====================================
If you HAVE the polar coordinates and you want to find the Cartesian ones,
then do it like this:
You have (R, A) .
You want to find 'x' and 'y' .
x = R cos(A)
y = R sin(A)