Question

Identify the following 3-D object.

$
  (a){\text{ cylinder}} \\
  {\text{(b) rectangular pyramid}} \\
  {\text{(c) right triangular prism}} \\
  {\text{(d) right rectangular prism}} \\
 $

Answer 1

Hint – In this question think of the properties of a right triangular prism as the figure given is a polyhedron which has 6 vertices, 9 edges and 5 faces. So choose from the option that which shape resembles a polyhedron with such properties.

Complete step-by-step solution -
As we see that the given 3-D object contains two parallel and congruent triangular faces and three rectangular faces perpendicular to the triangular ones.
So this is a polyhedron which has 6 vertices, 9 edges and 5 faces.
As we know that a right triangular prism is a prism with two parallel and congruent triangular faces and three rectangular faces perpendicular to the triangular ones. If the bases are horizontal, they are sometimes called the top and the bottom (faces).
All the properties of the given 3-D object match with the properties of the right triangular prism.
Hence the given 3-D object is a right triangular prism.
Hence option (C) is correct.

Note – Understanding of basic shapes always helps solving problems of this kind. If the shapes of cylinder, regular pyramid, right triangular prism and right rectangular prism are known, we could have easily approached the problem by the concept of option elimination. The basic shape outline of the right rectangular pyramid and right rectangular prism is depicted as.