1. EXAMPLE 1
Drawing a Net
Draw a net of the triangular prism.
SOLUTION
METHOD 1
Draw one base with a rectangle
adjacent to each side. Draw the
other base adjacent to one of the rectangles.

2. EXAMPLE 1
Drawing a Net
METHOD 2
For the rectangular faces, draw
adjacent rectangles. Draw the
bases on opposite sides of one rectangle.

3. EXAMPLE 2
Using a Net to Find Surface Area
Storage Chest
You are painting a storage chest with the given dimensions. Find the surface area to be painted.

4. EXAMPLE 2
Using a Net to Find Surface Area
SOLUTION
Draw a net of the chest. The area of each square face is 15 in. 15 in. = 225 in.2 The area of each rectangular face is 30 in. 15 in. = 450 in.2
There are two square faces and four rectangular faces, so the surface area is in in.2 = 2250 in.2

5. EXAMPLE 2
Using a Net to Find Surface Area
ANSWER
The surface area of the storage chest is 2250 square
inches.

6. EXAMPLE 3
Using a Formula to Find Surface Area
Find the surface area of the triangular prism.
S = 2B + Ph 1 2
= 2( ) + ( )15
= 660
ANSWER
The surface area of the prism is 660 square centimeters.

7. Finding the Surface Area of a Cylinder
EXAMPLE 4
Finding the Surface Area of a Cylinder
Packaging
Find the surface area of the can
of sloppy joe sauce.
SOLUTION
The radius is one half the diameter, so r = 4 cm.
S = 2πr2+ 2πrh
Write formula for surface area.
= 2π(4)2 + 2π(4)(10.7)
Substitute 4 for r and 10.7 for h. ≈
Evaluate using a calculator.
ANSWER
The surface area of the can is about 369 square
centimeters.

8. GUIDED PRACTICE
for Examples 1, 2, 3, and 4
Draw a net of the solid. Then find the surface area. Round to the nearest tenth. Check your answer for reasonableness. 1.
ANSWER
222 ft2

9. GUIDED PRACTICE
for Examples 1, 2, 3, and 4
ANSWER
384 m2

10. GUIDED PRACTICE
for Examples 1, 2, 3, and 4
ANSWER
in.2