GeoGebra: Fractional Lengths in Triangles and Prisms IM 6.4.14
GeoGebra

“Fractional Lengths in Triangles and Prisms” from IM Grade 6 by Open Up Resources and Illustrative Mathematics.

GeoGebra: Triangles with 3 Common Measures IM 7.7.8
GeoGebra

“Triangles with 3 Common Measures” from IM Grade 7 by Open Up Resources and Illustrative Mathematics.

GeoGebra: Drawing Triangles (Part 2) IM 7.7.10
GeoGebra

“Drawing Triangles (Part 2)” from IM Grade 7 by Open Up Resources and Illustrative Mathematics.

GeoGebra: Drawing Triangles (Part 1) IM 7.7.9
GeoGebra

“Drawing Triangles (Part 1)” from IM Grade 7 by Open Up Resources and Illustrative Mathematics.

GeoGebra: Finding Side Lengths of Triangles IM 8.8.6
GeoGebra

“Finding Side Lengths of Triangles” from IM Grade 8 by Open Up Resources and Illustrative Mathematics.

Inside Mathematics: 4th Grade Math – Classifying Triangles
Inside Mathematics (The University of Texas at Austin, Charles A. Dana Center)

In the lesson, Lewis re-engages fourth-grade students after an initial experience the week prior, which was focused on classifying and categorizing triangles.