12.4: Activity 12H
The three parallelograms below all have two sides that are 3 units long and two sides that are 7 units long. (a) Use the moving and additivity principles to determine the areas of the three parallelograms. (b) Can there be a formula for areas of parallelograms that is only in terms of the lengths of the sides?
Find a formula for the area of a parallelogram in terms of lengths of parts of the parallelogram.