Number of Edges
About this exercise
Counting the edges of a solid.
Example problems
A few of the problems this exercise asks. The printable worksheet holds ten fresh ones.
- How many edges does a Pentagonal Pyramid have?
- How many edges does a Triangular Prism have?
- How many edges does a Rectangular Prism have?
- How many edges does a Cone have?
Try it yourself first — open a section below only if you get stuck.
How to solve it
An edge is where two faces meet. Count the top, the bottom and the uprights separately.
Worked example
A cube has 4 edges on top, 4 below and 4 vertical, giving 12.
Common mistake
Missing the hidden edges. Drawings usually show them as dashed lines.