The following objects are quadrilaterals: 1) square 2) triangle 3) trapezoid 4) rhombus. Which set contains only quadrilaterals?

The set that contains only quadrilaterals includes the square, trapezoid, and rhombus. A quadrilateral is defined as a polygon with four sides.

The square is a specific type of quadrilateral that has all four sides of equal length and right angles. The trapezoid is another type of quadrilateral characterized by having at least one pair of parallel sides. The rhombus, similar to a square, has four sides of equal length but does not necessarily have right angles.

The triangle, on the other hand, has only three sides and does not qualify as a quadrilateral, which excludes any sets containing it from being correct.

Therefore, the only set that includes objects that are all quadrilaterals is the one consisting of the square, trapezoid, and rhombus, making it the correct answer.