If a quadrilateral has exactly one pair of sides parallel it must be a

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To determine what type of quadrilateral has exactly one pair of sides parallel, we can analyze the properties of different quadrilaterals.

1. Rectangle: A rectangle has two pairs of parallel sides. Therefore, a quadrilateral with exactly one pair of parallel sides cannot be a rectangle.

2. Rhombus: A rhombus has two pairs of opposite sides parallel. Therefore, a quadrilateral with exactly one pair of parallel sides cannot be a rhombus.

3. Square: A square has four pairs of parallel sides. Therefore, a quadrilateral with exactly one pair of parallel sides cannot be a square.

4. Trapezoid: A trapezoid is defined as a quadrilateral with at least one pair of parallel sides. Therefore, a quadrilateral with exactly one pair of parallel sides can be a trapezoid. In a trapezoid, only one pair of opposite sides is parallel, while the other pair is not parallel.

So, if a quadrilateral has exactly one pair of sides parallel, it must be a trapezoid.