Polar coordinates describe positions on the plane in terms of the distance from the turtle's home and the angle from 0 degrees. Polar coordinates measure degrees counter-clockwise from a 0 degree heading that is equivalent to 3 o'clock.

PHEADING reports the polar heading of the turtle. A heading of 0 degrees is equivalent to a Cartesian heading of 90 degrees. Set the polar heading with PSETHEADING.

See also SETP, PPOS, PANGLE, and PDIST.