1. Lesson 11-2
Nets and Surface Area

2. Different Views Perspective view of a cone
Different angle views of a cone
the side
(or from any side view)
the top
the bottom

3. Example: Different Views
Front
Left
Right
Back
Top
* Note: The dark lines indicated a break in the surface.

4. Sketches
Sketch a rectangular solid 7 units long, 4 units wide, and 3 units high using Isometric dot paper .
Step 1: Draw the top of a solid 4 by 7 units.

5. Sketches - continued
Step 2: Draw segments 3 units down from each vertex (show hidden sides with dotted lines).

6. Sketches - continued
Step 3: Connect the lower vertices. Shade the top of the figure for depth if desired. You have created a corner view of the solid figure.

7. Nets and Surface Area
Imagine cutting a cardboard box along its edges and laying it out flat. The resulting figure is called a net.
top
back
end
front
bottom =
A net is very helpful in finding the surface area of a solid figure.

9. Find all that apply.

10. Let’s look at another net.
This is a triangular pyramid.
Notice that all sides lay out to be triangles. =

11. Find the surface area of the figure using a net.
First, imagine the figure represented as a net.
Find the area of each face.
Find the sum of all the individual areas.
33 10 6 6 10
33 =
Surface area =
(6 x 10) + (6 x 10) + (6 x 10) + ½(6)(33) + ½ (6)(33) =
3 + 93 = 3

16. Sketch the net and Find the surface area of the figure using a net.

17. Sketch the net and Find the surface area of the figure using a net.

18. Sketch the net and Find the surface area of the figure using a net.