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:
rectangle
octagon
pentagon
circle
hexagon
triangle
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
Solid Shape
A solid shape is a shape that is 3-dimensional. They have height, width,
and depth.
square
pyramid
Examples of solid shapes:
sphere
cube
cylinder
cone
rectangular
prism
Solid shapes can have faces, edges, and vertices.
Face: The flat surface of the solid
face
Edge: The line segment formed where two faces meet
Vertex (corner): A point where two or more edges
come together to form a corner.
edge
vertex
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
point
A
Definition
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.
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.