Which statement describes a trapezoid?
a regular quadrilateral
an equilateral right triangle
a quadrilateral with exactly one pair of parallel sides
a quadrilateral with two pairs of parallel sides

First option isn't answer because if trapezoid has same sides we don't usually call it trapezoid. We call it square.

Second option isn't answer because something that has 4 sides cannot be equal to something that has 3 sides

Third option is true because trapezoid has exactly one pair of parallel sides.

Forth isn't the answer because if trapezoid had 2 parallel sides we would call it rectangle and not trapezoid.