This task is used as a warmup in geometry classes. The task focuses on classifications of triangles, and the postulates that come with the relationships between side lengths and angles. One problem asks students to construct an argument about scalene triangles and their angles. Students are also asked to find the midpoint of a line segment on a coordinate plane.

Microsoft Word version: 912Geometry_ClassifyTrianglesMidpoint_Warmup_Construct_1

PDF version: 912Geometry_ClassifyTrianglesMidpoint_Warmup_Construct_1


This warm up is created for geometry students learning about triangles. There are three problems, one asking students to find the midpoint of a segment on a coordinate plane, another asking students to construct an argument to justify a claim, and another asking students to classify triangles. Argumentation language is used in the first two problems, encouraging the use of evidence.

Microsoft Word version: 912Geometry_ClassifyTrianglesMidpoint_Warmup_Construct

PDF version: 912Geometry_ClassifyTrianglesMidpoint_Warmup_Construct


A template of the talk frame was used to plan a geometry lesson on finding the midpoint of a segment. The teacher recorded a paraphrased version of the question in the Think section, anticipated ideas to be contributed in the Talk Ideas section, which include using a ruler, folding paper, and solving algebraically to find a midpoint, and the pieces of information to be learned in the We Understand section. Students are asked to construct an argument on finding the midpoint of a line segment and use argumentation language to convince another person.

Microsoft Word version: 912Geometry_Midpoint_LessonPlan_Construct_Talk-Frame-Midpoint

PDF version: 912Geometry_Midpoint_LessonPlan_Construct_Talk-Frame-Midpoint