so polar coordinates are (r, θ), where r is the length of a straight line from origin to the point and θ is the angle to provide direction. r is the hypothenus of a right angled triangle can be found. by using pythagoras theorem. For θ, use tan-1 (y/x) to find it. But take note of where the quardrants the point lies in. For the second and the third quardrant, add 180 degrees or π. For the last quardrant add 2π.