Finding the area of trapezoids
http://illuminations.nctm.org/LessonDetail.aspx?ID=L580
A lesson plan for grades 6–8 Mathematics
Learn more
Help
Please read our disclaimer for lesson plans.
Legal
This catalog record is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 2.5 License. This license applies to the content of this page only and does not apply to the referenced website.
Students discover the area formula for trapezoids, as well as explore alternative methods for calculating the area of a trapezoid. Once students can identify trapezoids, they practice estimating the areas of the shapes. Then, working in groups, students find the actual area of trapezoids using a mathematical formula. Illuminations provides an activity sheet, an overhead, and detailed instructions for completing the lesson.
Students will:
- Measure rectangles and triangles and determine their areas.
- Use their knowledge of the area formula for rectangles to derive an area formula for trapezoids.
- Explore alternative methods for determining the area of trapezoids.
- Calculate the area of trapezoids, given the base and height.
North Carolina Curriculum Alignment
Mathematics (2004)
Grade 7
- Goal 3: Geometry - The learner will understand and use properties and relationships in geometry.
- Objective 3.02: Identify, define, and describe similar and congruent polygons with respect to angle measures, length of sides, and proportionality of sides.
- Goal 5: Algebra - The learner will demonstrate an understanding of linear relations and fundamental algebraic concepts.
- Objective 5.04: Develop fluency in the use of formulas to solve problems.
