Unit 7, Lesson 14
Surface Area of Right Prisms
Grade 7
Preparation
Lesson Narrative
In this lesson, students find surface areas of prisms, and they see that the structure of a prism allows for shortcuts in adding up the areas of the faces. They see that if the prism is sitting on its base, then the vertical sides can be unfolded into a single rectangle whose height is the height of the prism and whose length is the perimeter of the base. The purpose of the lesson is not to come up with a formula for the surface area of a prism, but to help students see and make use of the structure of the prism to find surface area efficiently (MP7).
- Calculate the surface area of a prism, and explain (in writing) the solution method.
- Comprehend that surface area and volume are two different attributes of three-dimensional objects and are measured in different units.
- Interpret different methods for calculating the surface area of a prism, and evaluate (orally and in writing) their usefulness.
Let’s look at the surface area of prisms.
Required Preparation
Assemble the net from the blackline master to make a prism with a base in the shape of a plus sign. Make sure to print the blackline master at 100% scale so the dimensions are accurate. This prism will be used for both the warm-up and the following activity.