How do you work out the area of a parallelogram? Students are provided with a dynamic representation of a parallelogram which they use to explore the area. By locking the area, students see that infinitely many parallelograms still exist, however they all have the same base and height. Students are then provided with an animation that helps explain their observations.
The purpose of this activity is for students to discover the formula for the area of a parallelogram through exploration and understanding. Students then test and evaluate their formula.
About the Lesson
Students start with a free-form parallelogram. The area is displayed on screen. Students then lock down the area and explore. Infinitely many parallelograms can be formed, however they all have the same base and height measurements. This provides the clue to students about how the area might be calculated. Students are then able to launch a step by step animation that helps them see the 'why'. Students establish a formula and test to see if their formula works!