The term "geometric shape" refers to any shape that remains virtually unchanged if it is moved around, flipped or reflected off of a surface. When manipulated, a geometric shape does not create a new shape; it remains intact. Examples include the circle, square, triangle, rectangle, hexagon and octagon.
Two geometric shapes that share the same basic shape are called "similar to each other." If both shapes are the same size, they are called "congruent." Geometric shapes can be two-dimensional or flat. They can be three-dimensional, meaning they possess depth and volume. Geometric shapes are also broken down into further distinctions based on their properties.