Answer:
Trapezoid:
A trapezoid is defined as a quadrilateral with at least one pair of parallel sides, when the trapezoid as equal legs, it's called an isosceles trapezoid.
Bases of a trapezoid:
The bases of a trapezoid are the pair of parallel sides, both of them are called base, the longer one is the major base, and the shorter one is the minor base.
Legs of a trapezoid:
The legs of a trapezoid are the nonparallel sides, because if they were parallel, that wouldn't be a trapezoid, it would be another quadrilateral.
Median of a trapezoid:
The median of a trapezoid is a segment that connects the midpoints of the legs. Remember that medians are always line that intercept midpoints.
Isosceles trapezoid:
As we said before, an isosceles trapezoid are those which have legs with equal legs. The name isosceles refers to equality.
Therefore, the right matches are
1. Trapezoid: A quadrilateral with at least one pair of parallel sides.
2. Bases of a trapezoid: The parallel sides.
3. Legs of a trapezoid: The nonparallel sides.
4. Median of a trapezoid: The segment connecting the midpoints of the legs.
5. Isosceles trapezoid: A trapezoid with legs of the same length.