[?] Combine plots made in a Do loop?

Questions
1

Is there a way to use Show, e.g. Show[ Do[Graphics3D[ .. ],{i,1,n}]]?

2

Write Table instead of Do:

Show[Table[
  Graphics3D[Polygon[{{0, 0, 0}, {1, 0, 0}, {1, 1, i}}]], {i, 0, 1}]]

or, even shorter, move Table inside Graphics3D and forget about Show:

Graphics3D[
 Table[Polygon[{{0, 0, 0}, {1, 0, 0}, {1, 1, i}}], {i, 0, 1}]]
3

Many thanks!