3D Shapes

3D shapes Basics

• 3D shapes are figures that have three dimensions: height, width, and depth.
• Examples include cubes, cuboids, spheres, cylinders, cones, pyramids, and prisms.

Key Properties

• Each 3D shape has faces, edges, and vertices.
• A face is a flat surface of a 3D shape.
• An edge is the line segment where two faces meet.
• A vertex is a point where three or more edges meet.

Cubes and Cuboids

• A cube has six equal square faces, twelve edges, and eight vertices.
• A cuboid has six faces. The opposite faces of a cuboid are identical. It has twelve edges and eight vertices.

Spheres and Cylinders

• A sphere doesn’t have any faces, edges, or vertices. Its surface is smooth and round.
• A cylinder has two circular faces and one curved face. It doesn’t have any edges or vertices.

Cones and Pyramids

• A cone has one circular face, one vertex, and no edges.
• A pyramid has a polygonal base and triangular faces that meet at a common vertex. The number of faces is one plus the number of sides in its base.

Prisms

• A prism is a 3D shape which has two identical end faces that are parallel, and rectangular faces connecting them. The cross-section along its length is the same as the shape of the end faces.
• A cube or a cuboid is a prism because their ends are rectangles or squares.

Volume and Surface Area

• The volume is the amount of space inside a 3D shape. It’s measured in cubic units.
• The surface area is the total area of the surface of a 3D shape. It’s measured in square units.
• To find the volume or surface area of these shapes, it’s important to know their formulae.