By definition, a regular polygon has all interior angles the same, but a concave polygon has some interior angles that are not identical. Also, it violates the axiom that all vertices lie on a circle.
While it is possible to construct a polygon with equilateral sides, to be concave would require a form that is equally convex and laterally opposite. (An example is a 'solid arrow shape.')
No. There can be no regular concave polygon.
A concave quadrilateral would be a non-convex quadrilateral. * * * * * Also known as delta or arrowhead or chevron.
A concave quadrilateral - like an arrowhead or chevron.
A regular polygon has all its angles of equal measure, and its sides of equal length. In the case of a quadrilateral, that would mean a square. A concave quadrilateral must have at least one reflex angle and so cannot be a square. So it cannot be regular.
yes it will...
A chevron or arrowhead.
A concave quadrilateral. An arrowhead or a delta, for example.
No. A trapezoid has two parallel sides. This is not possible in a concave quadrilateral.
It would be a concave quadrilateral The link below has some pics.