Convert between rectangular (x, y) and polar (r, angle) coordinates. Pick the direction and enter the two values.
Usage Tip
Polar form makes rotation and scaling easy; rectangular form makes adding coordinates easy.
x = r·cos(angle), y = r·sin(angle)
The two forms describe the same point and convert directly into each other.
Rectangular to polar: enter x then y.
Polar to rectangular: enter r then the angle in degrees.
Rectangular coordinates describe a point by how far it sits along x and y, while polar coordinates describe it by its distance from the origin, r, and the angle it makes with the positive x axis. The radius is the square root of x squared plus y squared, and the angle comes from the arctangent of y divided by x, adjusted for the quadrant the point is in.
Going the other way, x equals r times the cosine of the angle and y equals r times the sine of the angle. Check whether your angle is in degrees or radians before entering it, since mixing the two is the most common source of wrong answers. At the origin the radius is zero and the angle has no meaningful value.