A trapezium has parallel sides of length equal to a and b (a < b), and the distance betweenthe parallel sides is the altitude h. The extensions of the non-parallel lines intersect at apoint that is a vertex of two triangles that have as sides the parallel sides of the trapezium.Express the areas of the triangles as functions of a; b and h.
什么叫"that is a vertex of two triangles that have as sides the parallel sides of the trapezium"……别的都好懂……
P.S.26号川大化院夏令营有没有组队的？