Problem:
Trapezoid , with bases and , has side lengths , , , and . Let diagonals and intersect at , and let and be the midpoints of and , respectively. Find the area of quadrilateral .
Problem:
Trapezoid , with bases and , has side lengths , , , and . Let diagonals and intersect at , and let and be the midpoints of and , respectively. Find the area of quadrilateral .
Solution:
Note that is a midline of triangle , so is parallel to and . We also have that is parallel to , and so is a parallelogram. From this, we have as well, so . It follows that the height from to is of the height from to . We can calculate that the height from to is , so the height from to is . Therefore is a parallelogram with base and height , and its area is .