Geometry Basics

Plane

• A flat, two-dimensional surface that extends infinitely far.

• A three-dimensional object with length, width, and height.

• A curved surface that can be defined by a single equation.

• A geometric figure with only length and width, but no area.

Line

• A straight one-dimensional figure having no thickness and extending infinitely in both directions.

• A curved two-dimensional shape that encloses space.

• A solid three-dimensional object with length, width, and height.

• A point that has no dimensions and represents a location.

Circle

• A round plane figure whose boundary consists of points equidistant from the center.

• A polygon with three sides.

• A shape with four equal sides and angles.

• A figure with no edges or vertices.

Angle

• A figure formed by two rays sharing a common endpoint, called the vertex.

• A straight line that extends infinitely in both directions.

• A closed figure with three sides and three angles.

• A shape with four equal sides and angles.

Point

• An exact location in space, having no dimensions.

• A geometric shape with length and width.

• A solid object with volume.

• A line that extends infinitely in both directions.

Perpendicular Lines

• Lines that intersect at a right angle (90 degrees).

• Lines that run parallel to each other.

• Lines that intersect at an acute angle.

• Lines that never meet.

Ray

• A part of a line that starts at a point and extends infinitely in one direction.

• A straight line that connects two points.

• A segment of a line that has a fixed length.

• A line that curves and does not have a defined direction.

Parallel Lines

• Lines that intersect at a point.

• Lines in a plane that do not meet; they are always the same distance apart.

• Lines that are perpendicular to each other.

• Lines that curve away from each other.

Obtuse Angle

• An angle that is less than 90 degrees.

• An angle that is exactly 90 degrees.

• An angle that is more than 90 degrees but less than 180 degrees.

• An angle that is more than 180 degrees.

Degree

• A unit of measurement of angles, one three-hundred-and-sixtieth of the circumference of a circle.

• A unit of temperature measurement in Celsius.

• A term used to describe the level of education attained.

• A type of geometric shape with three sides.