Lesson 1

Discover

 

In Module 5, one important question asked when making models was this: How much material is needed? If you are referring to the object’s surface, this question is really asking this: What is the surface area of the model?

 

In Exploring Surface Area, Volume, and Nets—Use It, you will investigate what surface area means. Click on the button and use the information to complete Try This 1.

 

Try This 1

 

Select the “Use It 1: Nets” tab of the applet to begin each investigation.

 

Investigate the following three-dimensional objects:

• rectangular prism
• rectangular pyramid
• triangular pyramid

Answer the following questions for each object. You can organize your responses in a chart similar to the one that follows.

1. Select a 3-D object from the area showing all six objects, and then choose the correct net for that object from the choices given. (Hint: Use the slider from the applet to help identify the correct net.) Sketch the net in your chart.
   
   
2. Use either the “Use It 1: Nets” or “Use It 2: Views” tab from the applet to help answer these questions:
   1. How many faces does the net have? 
   2. What 2-D shape does each face have?
      
      
3. What 2-D area formula could you use to find the area of each face?
   
   
4. Describe a strategy you could use to find the total surface area of the 3-D object.
   
   

   	Rectangular Prism	Rectangular Pyramid	Triangular Pyramid
   Sketch of Net
   Number and Shape of Each Face
   Formulas Used to Find the Area of Each Face
   Strategy Used to Find the Total Surface Area of the 3-D Object

Save your responses to your course folder.

 

Share 1

 

Share your responses to the Try This 1 questions with a partner or with a group of people. How did the strategies identified to find the surface area of the 3-D object compare? After comparing responses, discuss the following questions:

• What is the difference between an area of a 2-D shape and the surface area of a 3-D object?
  
  
• How can a net be used to help find the surface area of a 3-D object?

As you work on Share 1, refer to the Share Rubric. This information will help you understand what your teacher is expecting.

 

If required, save a copy of your discussion in your course folder.