Academy, Khan. “Decomposing Shapes to Find Area (Add) | Math | 3rd Grade | Khan Academy.” YouTube, YouTube, 13 June 2016, www.youtube.com/watch?time_continue=3&v=JTg8gyQ37pM.
Schersten, Ben, et al. “A Long Way Down: Designing Parachutes.” EiE Curriculum , 2011, www.eie.org/eie-curriculum/curriculum-units/long-way-down-designing-parachutes