This activity lets students practice classifying triangles by angles, (acute, right, obtuse), and by sides, (equilateral, isosceles, and scalene). There are two pages. One page is the triangle sort and the other page is the directions for the activity. (You only have to make but one copy of the directions for yourself but, I make one set for my class and laminate them for use for years to come. That way my students can follow along with me and then be able to return to the directions whenever necessary. It can be a partner, group, or individual activity. Other materials needed: glue, long piece of construction paper.