There is no polygonal shape which has exactly those angles. It is possible for a concave polygon with 6 or more vertices to have the given angles.
a shape with 7 vertices
A square, rectangle.
Depends on the shape. A right triangle has one right angle, a rectangle has 4, an equilateral triangle has none, a circle has no angles. There are polygons with more than 4 right angles, and there is no limit on how many, but those with more than 4 are not convex.
The number of vertices does not determine the number of faces. If the shape with 6 vertices was a quadrilateral based bipyramid, it would have 8 faces. A hexagonal based pyramid has 7 vertices and 7 faces. So more vertices does not necessarily imply more faces.
A star is not a specific shape: it is a generic word for a shape which has an even number of vertices. The interior angles at alternate vertices are usually reflex angles. A star can have six or more vertices.
There is no polygonal shape which has exactly those angles. It is possible for a concave polygon with 6 or more vertices to have the given angles.
Any shape with two or more vertices can have one or more pairs of equal angles. The simplest of these is a symmetric lenticular shape with just two vertices.
There is no polygonal shape which has exactly those angles. It is possible for a concave polygon with 6 or more vertices to have the given angles.
If the question is about a plane shape with exactly 3 right angles it could be an irregular polygon of 5 or more sides. If the shape can have more than 3 right angles then a square or rectangle are also possible. Finally, in 3 or more dimensions, a polyhedron with any number of faces can have 3 or more right angles.
The shape could be a parallelogram (including a rhombus). Some kites would satisfy these requirements. And it is, of course, possible to have a shape with 5 or more vertices (i.e. more than 4 angles) that contains two acute and two obtuse angles.
The simplest shape that can have 2 right angles is a rectangle or a square. You can make an unlimited number of more complex shapes, though. A house shape is a pentagon with 2 right angles--you could even make it with 3 right angles.
A shape with four sides has four vertices and a shape with three sides has three vertices, so a shape with four sides has more vertices than a shape with three sides.
a shape with 7 vertices
A square, rectangle.
Depends on the shape. A right triangle has one right angle, a rectangle has 4, an equilateral triangle has none, a circle has no angles. There are polygons with more than 4 right angles, and there is no limit on how many, but those with more than 4 are not convex.
A shape with more than four sides, but has four right angles. There is no name for it.