Compared with what? It is the bottom and the vertex.
In this way, the height is the line segment passing through the vertex of the graph and perpendicular to the vertical point of the bottom opposite to the vertex (or the extension line of the bottom).
For example:
1 vertices of a triangle are only 1 bottoms (or their extension lines) high;
1 vertex passing through a quadrilateral is the height of two bottoms (or their extension lines);
1 vertex passing through the Pentagon is three bases (or their extension lines) high;
......
The height of 1 vertices passing through the n polygon is n-2 bottoms (or their extension lines).