This activity is modified for online learning.[br][br]The teacher will give a demonstration of each of the applets before you are given time to explore them.

After watching the demonstration, try this:[br][br]1. Move point A to make AB=4. [br] ABCD will be a 4 x 4 square.[br][br]2. Move point E to rest directly above point A.[br][br]3. Move the plane to change the size of the cross section, square GHIJ.

This activity was inspired by [br][br]illustrative mathematics, geometry, unit 5, lesson 3,[br][url=https://im.kendallhunt.com/HS/teachers/2/1/15/index.html][br]https://im.kendallhunt.com/HS/teachers/2/5/3/preparation.html[br][br][/url]Licensed under the Creative Commons Attribution 4.0 license, [br][br]https://creativecommons.org/licenses/by/4.0/[br][br][br]Modifications were made by Mark E. Vasicek to accommodate online instruction.