Plane geometry

Plane geometry studies the properties, measurements, and relationships of points, lines, angles, and shapes that exist in a two-dimensional plane. It includes reasoning about congruence, similarity, parallelism, and the calculation of lengths, areas, and angles.

Important properties

• All figures are two-dimensional (2D) and lie in a flat plane.

• Basic objects include points, lines, rays, segments, and angles.

• Figures can be classified as polygons (triangles, quadrilaterals, etc.), circles, and other shapes.

• Key concepts include congruence (same shape and size), similarity (same shape, different size), and symmetry.

• Plane geometry often involves proofs and logical reasoning.