1. Warm Up Problem  Which of the following statements is true for the equation 6x = 78?  A) To find the value of x, subtract 6 from 78.  B) To find the value of x, multiply 6 by 78.  C) To find the value of x, add 6 and 78.  D) To find the value of x, divide 78 by 6.

2. Surface Area of Rectangular Prisms Lesson 10-3

3. Objectives  I can find the surface area of rectangular prism.  I can explain the difference between surface area and volume.

4. Vocabulary  surface area – the sum of the areas of the faces

5. Example 1 - Notes  Find the surface area of the rectangular prism.  Find the area of each pair of faces (red).  Add them up: 48 + 48 + 56 + 56 + 42 + 42 = 292  So, the surface area is 292 sq. meters.

6. Example 1 – Guided Practice  Find the surface area of the rectangular prism.

7. Example 2 - Notes  Find the surface area of the rectangular prism.  Use the formula for surface area:  S.A. = 2 l h + 2 l w + 2hw  Front and back:  2(7)(4) = 56  Sides:  2(5)(4) = 40  Top and bottom:  2(5)(7) = 70  Add them up:  56 + 40 + 70 = 166ft²

8. Example 3 - Notes

9. Example 2 & 3 – Guided Practice  Find the surface area of the rectangular prism.

10. Example 4 - Notes  A geode is being sent in a gift box. The box measures 7 inches long, 3 inches wide, and 16 inches tall. What is the surface area of the box?  S.A. = 2 l h + 2 l w + 2hw  S.A. = 2(7)(16) + 2(7)(3) + 2(3)(16)  S.A. = 14(16) + 14(3) + 32(3)  S.A. = 224 + 42 + 96  S.A. = 362 sq. in.

11. Example 4 – Guided Practice  Elian keeps his model car in a glass display case. What is the surface area of the glass, including the bottom?