One Way to Look at Triangles

Students identify, describe, and draw acute, right, and obtuse triangles. Note: Activity 2 was updated in the Teacher Edition PDF and in the Teacher Presentation Screens on 1/12/2026.

By Amplify Classroom

Grades: 4th Grade

Subject: Math

Learning goals: Today’s Goals • Identify and draw acute, right, and obtuse triangles. • Analyze and sort triangles based on the sizes of their angles. Materials Manipulative Kit: protractors, rulers or straightedges (optional); Classroom materials: tracing paper (optional); Centers Resources: Shape Cards, Grade 4 PDF (from Lesson 12)