What is a plane figure?

A plane figure is a two-dimensional shape that lies flat on a plane surface. This means that it has only length and width, but no thickness. Examples of plane figures include triangles, squares, rectangles, circles, and polygons.

Plane figures are characterized by their various properties, such as perimeter, area, angles, and sides. The perimeter of a plane figure is the sum of the lengths of its sides, while the area is the amount of space inside the figure. Angles in a plane figure are formed where two sides meet, and the number of sides determines the shape of the figure.

Plane figures play an important role in geometry and mathematics, as they are used to describe and classify shapes, solve problems, and apply mathematical concepts in real-world situations. They also form the basis for understanding more complex geometric shapes and concepts.