Math Curriculum

Level C
Unit: Geometry
Key Lesson 6.1.9 Formula for the Area of a Triangle

Lesson topic: Finding the area of triangles

Instructor Materials

  • Teacher guide
  • Slides
  • Practice Problems resource
  • CCRS standard: 6.G.1, 6.EE.2a, 6.EE.2c
  • Learning goal: Compare, contrast, and critique (orally) different strategies for determining the area of a triangle. Generalize a process for finding the area of a triangle, and justify (orally and in writing) why this can be abstracted as 1/2 × b × h. Recognize that any side of a triangle can be considered its base, choose a side to use as the base when calculating the area of a triangle, and identify the corresponding height.
  • 6.1 Assessment and Practice Problems

Student Materials

Related Lessons


If students need additional lessons before this key lesson, use these supplemental lessons.

Review and Extend

Use these supplemental lessons if needed after teaching this key lesson.




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