A square based pyramid is a 3-d object. It does not have a 2-d name!
Chat with our AI personalities
Five faces, in all.
3D = Pyramid 2D = Triangle
Yes. Just like a square is 2D.
A flat (2D) shape triangle has 3 straight edges. A triangular pyramid has 6 straight edges. A square pyramid has 8 straight edges. (Note, some vertical edges have already been counted as you move from one face to the next.)
Heptagonal pyramid * * * * * No. A heptagonal pyramid has 8 vertices. You need a hexagonal pyramid or a pentagonal dipyramid for 7 vertices. Or, in 2d, a heptagon.