Lesson Plan

# Calculating Surface Area of Solids

Use digital tools to explore 3D shapes and break them down into 2D nets to calculate surface area. Jason G.
Classroom teacher
My Subjects Math, Science
Objectives

Students will be able to:

• Break down 3D prisms, pyramids and cylinders into 2D nets
• Calculate the surface area of prisms, pyramids and cylinders
Subjects
Math

#### 1 Review area of 2D shapes

Use Kahoot to do a quick review game of area of 2D shapes (triangles, rectangles, circles). Teacher can create their own or search for an existing game on area.

#### 2 Explore 3D shapes

Ask students to play around with the app and explore different shapes. Demonstrate the net feature. Ask them to describe the nets of:

• A rectangular prism
• A rectangular pyramid
• A triangular prism
• A cylinder

More shapes can be assigned depending on the level of the students. Specifically, students should note what 2D shapes make up the 3D shapes.

#### 3 Calculate Surface Area

For this step, students will use the 3D graphics feature of Geogebra. Depending on their level of comfort with Geogebra, student may need help or follow along as the teacher demonstrates. Students should attempt to create cylinders, pyramids and prisms. Geogebra will automatically calculate the area of each face. Students should use the feature to display the 2D net of each 3D shape. They can, then, calculate the area of the 2D net by hand (or calculator), and compare their results with those generated by Geogebra.

#### 4 Wrap-up

Review calculating surface area of solids using Kahoot. In order to make the game flow and stay under Kahoot's 2 minute per question time limit, the solids should probably be fairly simple, with whole number dimensions. Questions could also ask how many different faces a solid has. This would make the game move quickly.