What is a square-based pyramid?
A pyramid is a 3D shape that has a base and triangular sides. For example, a square-based pyramid also has a square base which it rests upon.
The Egyptian pyramids are an excellent example of square-based pyramids.
What are the properties of a square-based pyramid?
- 3D shape
- Four triangular sides that are all the same shape and size
- Square base
- Five sides in total
- Five vertices
- Eight edges
Types of square-based pyramids
Square-based pyramids can be divided into three categories: right-square pyramids, oblique-square pyramids, and equilateral-square pyramids. We can distinguish the square-based pyramids based on the lengths of their edges, the position of the apex, and so on. Let’s explore the three types of square-based pyramids below.
Right-square pyramid
If the apex of the square-based pyramid sits directly above the center of the base, in other words, it is perpendicular to the base; we can classify it as a right-square pyramid.
Oblique-square pyramid
If the apex of the square-based pyramid is not aligned directly above the center of the base, we can classify it as an oblique-square pyramid.
Equilateral-square pyramid
If all of the triangular faces of the square-based pyramid have equal edges, then we can classify it as an equilateral-square pyramid.
What do you call a pyramid with a square base?
A square-based pyramid is a polyhedron, a 3D shape with flat polygons as its sides.
It can also be called a pentahedron because it has five sides – “Penta” is Latin for 5.
If all of the triangular sides of the pyramid are equilateral, with equal sides and angles, the square-based pyramid is known as a Johnson solid. It is because all of its edges are equal in length.
Vocabulary
Apex – the highest point of a shape.
Base – the bottom of a shape.
3D (three-dimensional) shape – a solid shape that occupies space and has three dimensions: length, depth, and width.
Edge – an edge is where two faces meet.
Face – a flat or curved surface on a shape.
Net – what a shape looks like if it is opened out flat.
Vertex – a corner where edges meet.
