$\"\"$

A quadrilateral is a trapezoid if exactly one pair of opposite sides are parallel.

Use slope formula to determine if atleast one pair of opposite sides are parallel.

The slope formula is $\"\"$ .

Slope of $\"\"$ (Substitute $\"\"$ )

$\"\"$ (Simplify)

Slope of $\"\"$ (Substitute $\"\"$ )

$\"\"$ (Simplify) $\"\"$

Slope of $\"\"$ (Substitute $\"\"$ )

Since slopes of $\"\"$ and $\"\"$ are equal, $\"\"$ .

Therefore, QRST is a trapezoid. $\"\"$

QRST is a trapezoid.