• Don't you hate the way those practice sheets all show the base and heights of the figures your students are calculating the area?
• Don't you hate the fact that the bases are always on the bottom, and the heights are always in the middle?
• Don't you wish your students could do something more than "plug & chug" some numbers to get an answer?
If these are your issues (at least, in mathematics; I don't do anything else...) then you should definitely check out these activities. There are all kinds of neat challenges, including make 5 different trapezoids with an area of 16 square centimeters, using the different sides of a triangle to identify the bases and heights and calculate area, and re-assembling parallelograms to become rectangles, among other things. Please, PLEASE let your students do something interesting and challenging while learning this topic, okay?