Identify prisms and pyramids
To identify a solid, look first at its bases and then at the faces that connect them.
1) Check the bases
- A prism has two congruent, parallel bases.
- A pyramid has one base and all other faces meet at a single vertex or apex.
2) Look at the side faces
- In a prism, the side faces are parallelograms or rectangles in a right prism.
- In a pyramid, the side faces are triangles.
3) Use the shape of the cross-section and edges
- If the solid keeps the same cross-section all the way through, it is usually a prism.
- If the faces narrow to one point, it is a pyramid.
4) Make the identification
Name the solid by its base shape:
- triangular prism
- rectangular prism
- triangular pyramid
- square pyramid
Quick check
Count the bases: two means prism, one means pyramid. Then verify the side faces match that choice. If the answer must be simplified, write the final name clearly and only once.