A plane figure is a two-dimensional shape that exists on a flat surface. It can be described by its length, width, and AREA. The crossword solutions for the term plane figure include polygon (7 letters), decagon (7 letters), SQUARE (6 letters), PILOT (5 letters), AREA (4 letters), and CIRCLE (6 letters). A polygon is a closed shape with three or more sides, while a decagon is a polygon with ten sides. A SQUARE is a four-sided polygon with all sides equal in length. A PILOT is a person who operates an aircraft, but it is not a plane figure. AREA is the measure of the space inside a two-dimensional shape, and a CIRCLE is a round plane figure with no sides.