Unit 3: 3D Shapes Vocab

Front

What is a 3D shape?

Back

A three-dimensional shape (3D shape) is an object that has depth, width, and height, unlike 2D shapes which only have length and width.

Front

Define a prism.

Back

A prism is a solid shape with two identical ends and flat sides. The sides are parallelograms, and the shape is named after its base.

Front

What is a pyramid?

Back

A pyramid is a solid shape that has a polygonal base and triangular faces that meet at a common point (the apex).

Front

What is the difference between a radius and a diameter?

Back

The radius is the distance from the center of a circle to any point on its circumference, while the diameter is twice the length of the radius and passes through the center.

Front

What shape is formed when a triangle is rotated about one of its sides?

Back

A cone is formed when a right triangle is rotated about one of its legs.

Front

What is the horizontal cross-section of a cylinder?

Back

The horizontal cross-section of a cylinder is a circle.

Front

Define a sphere.

Back

A sphere is a perfectly round 3D shape where every point on the surface is equidistant from the center.

Front

What is a face in geometry?

Back

A face is a flat surface on a 3D shape. For example, a cube has 6 faces.

Front

What is an edge in geometry?

Back

An edge is a line segment where two faces meet in a 3D shape.

Front

What is a vertex in geometry?

Back

A vertex is a point where two or more edges meet in a 3D shape.