This is an arrowhead quadrilateral.
A rhombus is a quadrilateral with all sides of equal length. A reflex angle is an angle greater than 180 degrees. A rhombus does not have a reflex angle because the sum of its interior angles is always 360 degrees, which means all its angles are less than 180 degrees.
It could be a kite, an arrowhead or an irregular quadrilateral with a right angle - which has no specific name.
Reflex angle
A reflex angle is between 180 degrees to 360 degrees
concave
Reflex angle
The only quadrilaterals with a reflex angle are arrowheads (or chevrons).
It is a hexagon with a reflex angle.
It is also called an arrowhead. It is a kite with one of the vertices between equal sides "pushed in" so that it becomes a reflex angle.
Yes
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.
No.
Any angle <360 degrees is possible, though it would be a concave quadrilateral if the angle were greater than 180 deg.
Yes - a chevron or arrowhead.
A concave pentagon.
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