[list][*][size=150]Require students to construct the objects.[/size][br][/*][size=150][*]Can be constructed from scratch.[br][/*][*]Contain opportunities for discussion.[br][/*][*]Encourage learning through investigation.[/*][/size][/list][br][size=150]Examples:[br][url=https://tube.geogebra.org/material/show/id/811869]https://tube.geogebra.org/material/show/id/811869[/url][/size]