Question

An octagonal pyramid ... how many faces does it have, how many vertices and how many edges? A triangular prism ... how many faces does it have, how many vertices and how many edges? a triangular pyramid ... how many faces does it have, how many vertices and how many edges?

Answer 1

1: 8 faces and 9 with the base 9 vertices and 16 edges

2: 3 faces and 5 with the bases 6 vertices and 9 edges

3: 3 faces and 4 with the base 4 vertices and 6 edges

Hope this can help you.

Answer 2

• octagonal: 8 faces, 16 edges, 9 vertices
• triangular pyramid: 3 faces, 6 edges, 4 vertices
• triangular prism: 3 faces, 9 edges, 6 vertices

Explanation:

A pyramid has twice as many edges as faces, and 1 more vertex than faces.

Octa- means 8.

Tri- means 3.

a) An octagonal pyramid has 8 faces, 16 edges, and 9 vertices.

b) A triangular pyramid has 3 faces, 6 edges, and 4 vertices.

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A triangular prism will have 3 additional edges for the second "base", and 2 additional vertices.

c) A triangular prism has 3 faces, 9 edges, and 6 vertices.

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Additional comments

We have not counted the base as a "face." We have only counted those that meet at the point of the pyramid.

There are as many vertices on the base as there are faces, and there is one more vertex where all the faces meet.

There is one edge at the base for each face, and there is one edge from the base vertex to the point of the pyramid for each face--a total of two edges per face.

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A triangular pyramid is shown in the attachment.