# Introduction to geometry The geometry it is a branch (the oldest) of mathematics that focuses on measurement and the relationship between lines, angles, surfaces, solids, and points; in general, it is in charge of studying the properties of figures in the plane or space, such as: points, lines, planes, polygons, polyhedra, surfaces, among others.

This has its practical application in numerous areas, such as mechanics, astronomy, cartography, topography, ballistics, architecture, among others. It is useful in the preparation of designs (such as computational). Arguably, geometry is infiltrated in every facet of our daily life.

The fundamental concepts of geometry are point, line, and plane. From there others are derived such as ray, segment, vectors and plane.

• Fundamental figures: point, line and plane.
• Straight: segments, rays and vectors. On the plane, determine two half planes; their intersection determines the convex figures (such as the triangle).
• Using the concept of distance, the circle and the sphere.
• By using the semi-space they are defined: the dihedral, the prismatic space, the trihedron, the polyhedron angle and the polyhedra (tetrahedron, prism, pyramid and parallelepiped).
• The concept of a circle in space gives rise to the cone and the cylinder.