It is irregular because adjacent sides are not equal, and adjacent angles are not equal. Shape (d) is a trapezium and a quadrilateral. It has two equal sides and two pairs of equal angles, but is clearly irregular. The remaining shapes do not really have specific names.

Is a trapezium a regular or irregular shape?

Trapezium, describing a geometric shape, has two contradictory meanings: Outside the US and Canada: a quadrilateral with at least one pair of parallel sides (known in the US as a trapezoid) In the US and Canada: a quadrilateral with no parallel sides (known elsewhere as a general irregular quadrilateral)

Can trapezium be regular?

Trapezium. A trapezium has one pair of opposite sides parallel. A regular trapezium has non-parallel sides equal and its base angles are equal, as shown in the diagram.