7.5

3: Label the coordinates on graph paper, use the slope formula to see if the bases are parallel, and use the distance formula to see if the sides are congruent.

10: The length of the midsegment of a trapezoid is the average of the lengths of the bases.

11: This is the same as the previous problem, except you are solving for the length of a base instead of the length of the midsegment.

13: Plot the points on graph paper, and then use the distance formula to find the lengths of the bases.

22: Two of the sides are parallel.

25: Is it possible to draw a quadrilateral whose diagonals intersect at a right angle but that does not have four congruent sides?

28: Set up an equation showing that the midsegment length is the average of the length of the bases, and solve.