A cube has 4 flat surfaces (called faces) and 6 vertices (or corners).
rectangular prism
The solid figure that has 4 flat surfaces that are triangles is a tetrahedron. A tetrahedron is a polyhedron with four triangular faces, six straight edges, and four vertex corners. Each of the four faces of a tetrahedron is an equilateral triangle, making it a regular polyhedron.
A square has 4 flat surfaces.
Triangular prisim
A triangular based pyramid would fit the given description.
5 Flat surfaces 4 flat surfaces (3 for the sides and 1 for the base).
square
The question is somewhat confused. It has "... 6 flat SQUARE faces 2 are SQUARE and 4 are RECTANGLES ...." Assuming the first part is wrong, the shape is a cuboid.
There are 4 corners in a flat rectangle and 8 corners in a 3d rectangle(rectangular prism).Four.
rectangle
A square or quadrilateral.