Another common

**coordinate system**for the plane is the polar**coordinate system**. A point is chosen as the pole and a ray from this point is taken as the polar axis.For a given angle θ, there is a single line through the pole whose angle with the polar axis is θ (measured counterclockwise from the axis to the line).A

**Cartesian coordinate system**(UK: / k ɑː ˈ t iː zj ə n /, US: / k ɑːr ˈ t i ʒ ə n /) in a plane is a**coordinate****system**that specifies each point uniquely by a pair of numerical coordinates, which are the signed distances to the point from two fixed perpendicular oriented lines, measured in the same unit of length.