About Geometry
Mathematics grows by connecting definitions, patterns, models, calculations, and proof. This page builds the topic from basic ideas toward applications and deeper reasoning.
Points and Lines
Points mark locations and lines extend indefinitely.
Learn MoreAngles
Angles measure turns between rays.
Learn MorePolygons
Polygons are closed shapes made from line segments.
Learn MoreCircles
Every point on a circle is the same distance from its center.
Learn MoreArea
Area measures two-dimensional space inside a figure.
Learn MoreSolids
Three-dimensional objects occupy volume.
Learn MoreSymmetry
Symmetry describes transformations that preserve appearance.
Learn MoreCoordinates
Coordinates connect algebra and geometry.
Learn MorePoints and Lines
Segments and rays are related objects used to build more complex figures.
Angles
Right, acute, obtuse, straight, and reflex angles describe different amounts of rotation.
Polygons
They are classified by sides, angles, parallel lines, and symmetry.
Circles
Radius, diameter, circumference, and area are linked through pi.
Area
Complex shapes can often be decomposed into rectangles, triangles, and other familiar pieces.
Solids
Prisms, pyramids, cylinders, cones, and spheres have surface area and volume.
Symmetry
Reflection, rotation, and translation appear in art, architecture, nature, and mathematics.
Coordinates
Ordered pairs locate points, while equations can describe lines and curves.