# Geometry of Three-Dimensional Objects Activities for Middle School

Instructor: Heather Jenkins

Heather has a bachelor's degree in elementary education and a master's degree in special education. She was a public school teacher and administrator for 11 years.

Understanding the parts of three-dimensional shapes and how to calculate different measurements using them are important concepts in geometry. These activities will help your students explore the geometry of three-dimensional objects.

## Everyday Objects

Three-dimensional shapes are all around us. Students eating an ice cream cone, playing basketball, or wrapping a gift are all using three-dimensional objects. Consider using these activities to help students explore the relationship between three-dimensional and two-dimensional shapes, identify parts of three-dimensional shapes, and calculate the volume and surface area of three-dimensional objects.

## Exploring with Nets

Students will create three-dimensional shapes using paper nets of each shape.

### Materials

• Examples of three-dimensional shapes
• Copies of nets for geometric shapes
• Scissors
• Tape/glue
• Chart paper
• Markers

### Teacher Directions

• Show students examples of three-dimensional shapes, such as a tissue box (rectangular prism) or a globe (sphere).
• Tell students that they will be making three-dimensional shapes using nets, or flatten versions of three-dimensional shapes.
• Divide the class into small groups, and provide each group with copies of nets, chart paper, markers, scissors, tape/glue. Consider using nets of the following shapes:
• Rectangular prism
• Cube
• Cone
• Square-based pyramid
• Cylinder
• Hexagonal prism
• Dodecahedron
• Each group will cut out their nets and assemble the three-dimensional shapes by folding them and taping/gluing the appropriate sides together.
• Students will create a chart with their observations about the three-dimensional shapes. The chart should contain the following information:
• Drawing of the net for each three-dimensional shape
• Drawing of the assembled three-dimensional shape
• List of the two-dimensional shapes, and quantity of each, that make up the three-dimensional shape
• When students are finished, they will share their findings with the class.

### Discussion Questions

• How are the three-dimensional shapes you created the same and different?
• How do the types of two-dimensional shapes found in the nets of three-dimensional shapes contribute to their structure?

## Marshmallow Toothpick Shapes

Engage students in a hands-on activity to create three-dimensional shapes with toothpicks and marshmallows as they explore vertices, edges, and faces.

### Materials

• Three-dimensional objects (ex- dice)
• Copies of chart of three-dimensional objects
• Marshmallows
• Toothpicks
• Paper

### Teacher Directions

• Define 'vertex,' 'edge,' and 'face' for the class. Illustrate an example of a vertex, edge, and face on a three-dimensional object, such as a set of dice.
• Divide the class into pairs, and provide each pair with a copy of a chart of three-dimensional objects, marshmallows, and toothpicks.
• Have students recreate each three-dimensional shape using marshmallows and toothpicks. The marshmallows will represent the vertex where edges meet, and the toothpicks will represent edges.
• Consider having students create common three-dimensional shapes, such as rectangular prisms, and more complex shapes like octahedrons.
• Provide each pair with paper and have them create charts listing the number of vertices and edges and the number and shape of faces for each three-dimensional shape.
• When finished, have students discuss their findings.

### Discussion Questions

• How are the number of vertices, edges, and faces related to each other in different three-dimensional shapes?
• In what professions would people be concerned with understanding the vertices, edges, and faces of three-dimensional shapes.

## Measure the Volume/Surface Area

Have students take measurements to figure out the surface area and/or volume of different three-dimensional objects.

To unlock this lesson you must be a Study.com Member.

### Register to view this lesson

Are you a student or a teacher?

#### See for yourself why 30 million people use Study.com

##### Become a Study.com member and start learning now.
Back
What teachers are saying about Study.com

### Earning College Credit

Did you know… We have over 200 college courses that prepare you to earn credit by exam that is accepted by over 1,500 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level.