Calculating Surface Area of Solids
1 Review area of 2D shapes
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.
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.
Key Standards Supported
Know the formulas for the area and circumference of a circle and use them to solve problems; give an informal derivation of the relationship between the circumference and area of a circle.
Use facts about supplementary, complementary, vertical, and adjacent angles in a multi-step problem to write and solve simple equations for an unknown angle in a figure.
Solve real-world and mathematical problems involving area, volume and surface area of two- and three-dimensional objects composed of triangles, quadrilaterals, polygons, cubes, and right prisms.