Geometry in class


A point is an exact position or location on a plane surface.


A line has only one dimension. It continues forever in two directions.


Flat two-dimensional object.

Intersecting Lines

Two or more points that meet at a point are called intersecting lines.

Parallel Lines

Two lines in the same plane that never intersect.

Vertical Line

A line parallel to the sides of a page or sheet as distinguished from a horizontal line.

Horizontal Line

Parallel to or in the plane of the horizon or a base line.

Parallel Planes

Parallel Planes are planes in the same three-dimensional space that never meet.

Acute Angle

An angle that measures less than ninety degrees but more than zero degrees.

Obtuse Angle

An angle that measures more than 90 degrees but less than 180 degrees.

Right Angle

An angle of 90 degrees as in a corner of a square or at the intersection of two perpendicular straight lines.


A four sided flat shape with straight sides where all sides have an equal length.


A rectangle is a four sided flat shape where every angle is 90 degrees.


A round plane figure whose boundary consists of points equidistant from a fixed point.


Half a circle.


A symmetrical three dimensional shape, either solid or hollow,contained by six equal squares.


A plane figure with eight straight sides and eight angles.


A solid geometric figure with straight parallel sides and a circular or oval section.

Congruent Circles

Two circles with the same diameter.

Chord of a Circle

Geometric line segment whose endpoints both lie on the circle.

Central Angle of a Circle

Angles formed by any two radii in a circle. The vertex is the center of the circle.


A solid or hollow object that tapers from a circular or roughly circular base to a point.

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