https://www.geogebra.org/m/hp2a476z
Area Problem G
Teacher's Version 2
Quickstart Guide
[list=1][*]algebra view[br][/*][*]show slider u[br][/*][*]set u=3[br][/*][*]reset data[/*][*]bg of student's version: R196, G220, B230[/*][/list]
Student's Version 1 - an example
Student's Version 2 - a non-example
https://www.geogebra.org/m/dwyxwvxj
Student's Version 3 - an inverted stair
https://www.geogebra.org/m/bucbaahx