This follows on from Year 10 11th August Lesson

This is a Java Applet created using GeoGebra from - it looks like you don't have Java installed, please go to

How about:
Calculating the area of the rectangle. Then you can SHOW the area to check your calculations.
Making a connection between the red slider called size and the shape's size and area?
SHOW the area connection - it may help you to see it!
Making your own advanced applet, with a new shape and testing your calculations.