It has two regular polygons which can be used together to tessellate a plane.
Triangle, square and hexagon
Equilateral triangle, square and regular hexagon.
Equilateral triangle, square and regular hexagon.
Most regular polygons will not - by themselves. In fact, of the regular polygons, only a triangle, square and hexagon will. No other regular polygon will create a regular tessellation.
If it's interior angle is a factor of 360 then it will tessellate such as a square, a regular hexagon and an equilateral triangle.
No. Equilateral heptagons (7 sided figures) do not tessellate the plane. Not if no other polygons are allowed. But if you allow a (non-equilateral) pentagon then you might be able to tessellate the plane!
All sorts of figures. The only regular polygons that can tessellate by themselves are triangles, squares and hexagons. Irregular polygons such as rectangles, rhombuses, parallelograms and trapeziums will as well. Regular octagons combined with squares will. Other regular polygons can be combined with appropriate star-shapes to tesselate. There are also Penrose tilings which, although they cover the plane, are non-periodic in the sense that the pattern does not repeat itself if you move along. Finally there are many irregular shapes that will tessellate.
No
Square.
No.
No.