Geometry Study Guide Test Date: _____________________________  

Plane Shape A plane shape is a shape that is flat (known as a 2-dimensional shape). They have height and width.

Examples of plane shapes:

Solid Shape A solid shape is a shape that is 3-dimensional. They have height, width, and depth.

Examples of solid shapes:

Solid shapes can have faces, edges, and vertices.

Face: The flat surface of the solid

Edge: The line segment formed where two faces meet

Vertex (corner): A point where two or more edges come together to form a corner.

Polygons Some plane shapes are known as polygons.

Polygons are plane shapes that are closed (start and end at the same point) and made up of 3 or more line segments (sides). The sides of a polygon NEVER cross.

Polygons Not Polygons

rectangle octagon pentagon circle hexagon triangle

face

edge

vertex

cube cylinder cone rectangular prism

square pyramid

sphere

Congruent Shapes Congruent shapes are shapes that are EXACTLY the same size and shape.

Congruent Not Congruent

The shapes are congruent because they are the same

size and same shape!

The shapes are not congruent because they are not the same shape!

Lines and Angles

Figure Definition

point An exact location in space.

line A line that goes on and on forever in both directions.

line segment A part of a line. A line segment starts and stops between two endpoints.

ray A part of a line that goes on and on forever in ONE direction.

angle Formed by two rays with a common endpoint.

right angle An angle that measures exactly 90 degrees. Looks like a square corner.

acute angle An angle that measures less than 90 degrees.

obtuse angle An angle that measures greater than 90 degrees but less than 180 degrees.

perpendicular lines

Lines that cross and form square corners.

intersecting lines Lines that cross through the same point.

parallel lines Lines that are equal distance apart but never intersect.

A

Line of Symmetry When a figure is folded in a half along a line and the two parts match each other exactly. Some figures can have more than one line of symmetry.