Does the shape of a parachute change how fast it falls? You cut four shapes from plastic bags: a triangle, a square, a rectangle, and a circle. Each shape has the same surface area of 500 square centimeters. You attach strings and a small washer to each one. An assistant drops each parachute from a second-floor balcony while you time the fall with a stopwatch. You divide the drop distance by the time to calculate the speed. The round parachute falls the slowest and the triangular one falls the fastest.