Inspired by GeoGebra activity [color=#9900ff][color=rgb(51, 51, 51)][url=https://www.geogebra.org/m/efkjmh4e]Area of Parallelograms by Anthony OR 柯志明[/url][/color][/color].[br][br]A document describing the creation of the GeoGebra activity can be viewed below.