How many edges does a 70-gonal pyramid?

A 70-gonal pyramid consists of a base that is a 70-gon and has a vertex at the apex. The base has 70 edges, and each of the 70 vertices of the base connects to the apex, adding 70 more edges. Therefore, the total number of edges in a 70-gonal pyramid is 70 (base edges) + 70 (edges to the apex) = 140 edges.