Triangle
2 dimensional (plane) figures can have three or more straight edges as sides. 3 dimensional (solid) figures can have four or more plane sides (faces). They can have fewer sides if the sides are not straight.
a cube
a tetrahedron is a geometric solid that has 4 sides, all trianglular - it's like a pyramid with a triaglular base.
An 'oblate' is a 3-dimensional solid that resembles a ball that is being pushed together a little bit from two opposite sides.
Triangle
None it is impossible.
A Pyramid is a Geometric Solid whose sides are Triangles, that meet at its Apex. Pyramids can have Square bases (and thus 4 sides), or Triangular bases (and 3 sides).
2 dimensional (plane) figures can have three or more straight edges as sides. 3 dimensional (solid) figures can have four or more plane sides (faces). They can have fewer sides if the sides are not straight.
A 3 dimensional rectangle is a rectangular prism.
sides of the solid figure
the solid figure with six congruent sides isva cube
Regular solids have all sides the same, irregular solids have different sides.
A triangular prism (a pentahedron) has 3 sides on its base, 3 base vertices, and three top vertices.
a cube
a tetrahedron is a geometric solid that has 4 sides, all trianglular - it's like a pyramid with a triaglular base.
A side of a solid figure is called a face.