Definition
Apex
The apex is the special point of a cone or pyramid opposite its base.
Continue from this idea into connected AXIO math.
What it means
Start at the base and look away from it. The one point where the sloping faces or curved surface come together is the apex. It does not have to look like the “top”: turning the solid does not change which point is opposite the base.
Remember it
Base at one end, one meeting point at the other: that point is the apex.
Example
A square pyramid has one square base and four triangular side faces. All four triangles meet at the same point, so that point is the pyramid’s apex.
Watch for
A prism has two parallel matching bases, so it does not have one apex in this sense.
Common mix-up
Every apex here is a vertex, but not every vertex of a pyramid is its apex.
Exact meaning
For a pyramid, the apex is the vertex shared by all the triangular side faces and opposite the base. For a cone, it is the point where the curved surface narrows to one point, opposite the base.