Question

If we have a polyhedron, which of the following is true about its faces? Explain. [3 MARKS]

(i) It has 3 triangular faces.

(ii) It has 4 triangular faces.

(iii) It has 1 square and 4 triangular faces.

Answer 1

Solution: 1 Mark each

A polyhedron is a solid with flat polygonal faces, straight edges and vertices.

(i) This is not true. The minimum number of faces a polyhedron can have is 4. Hence 3 triangles cannot be the faces of a polyhedron.

(ii) This is true. A polyhedron with 4 triangles as faces is known as a regular tetrahedron.

(iii) This is true. A polyhedron with 1 square and 4 triangular faces is known as a square pyramid.