Depends on a concave what. There can be infinitely many right angles in concave shape that keeps going in and out before returning to its starting point.
None, because there is no such shape. There is a heptagon (7 sides) or an octagon (8 sides), and the answers will be different depending on what you meant. In their convex form, either can have at most 3 right angles. But a concave heptagon can have any number up to 6 right angles. A concave octagon can have up to 7 interior right angles. It can, in fact have all eight if reflex right angles (270 deg) are allowed.
It depends on how they are classified. They can have 1 to 4 acute angles, they can have 1 to 4 right angles, they can have 1 to 5 obtuse angles. The individual values of the angles will generate different pentagons. They can be regular or irregular. They can be convex or concave.
All angles < 180 degrees are concave. An acute angle is < 90 degrees. So, all acute angles are concave.
4 right angles, no other angles.
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.
It could have four if it is concave.
None, because there is no such shape. There is a heptagon (7 sides) or an octagon (8 sides), and the answers will be different depending on what you meant. In their convex form, either can have at most 3 right angles. But a concave heptagon can have any number up to 6 right angles. A concave octagon can have up to 7 interior right angles. It can, in fact have all eight if reflex right angles (270 deg) are allowed.
A concave irregular hexagon can have up to 6 right angles. A convex irregular hexagon can have up to 3 right angles.
An irregular (concave) polygon with 10 or more sides.
It depends on how they are classified. They can have 1 to 4 acute angles, they can have 1 to 4 right angles, they can have 1 to 5 obtuse angles. The individual values of the angles will generate different pentagons. They can be regular or irregular. They can be convex or concave.
Angles cannot be parallel.
It is an irregular, concave heptagon. But the shape has no special name.
A square. Or an irregular, concave shape with with 5 or more sides.
All angles < 180 degrees are concave. An acute angle is < 90 degrees. So, all acute angles are concave.
4 right angles, no other angles.
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.
None. Though there can be ten if the hexagons are concave hexagons.