Nets and Surface Area

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Lesson 11-2
Nets and Surface Area
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Definitions

• Surface Area- The sum of the areas of all faces
  and side surfaces of a three-dimensional figure.

• Net- A two-dimensional figure that, when folded,
  forms the surfaces of a three-dimensional object.

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Rectangular Prism
Square Pyramid
Pentagonal Prism
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Example 1
STECH A RECTANGULAR SOLID 3 UNITS HIGH, 4 UNITS
LONG, AND 5 UNITS WIDE USING ISOMETRIC DOT PAPER.

• Draw the top of the solid 4 by 5 units.

• Draw a segment 3 units down from each vertex.
  Hidden edges are shown by dashed lines.

• Connect the corresponding vertices.

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a.
a. Use rectangular dot paper to draw a net for
the prism.
Example 2
b. Find the surface area of the prism.
Continued on next slide..
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Ex. 2 Cont....
First, find the area of each rectangle.
b. FIND THE SURFACE AREA
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Example 3
Alegria is covering a box 40 cm. High, 30 cm.
Long, and 20 cm. Wide with expensive fabric to
use as a prop in a play. She wants to cover the
box using the smallest amount of fabric possible.
What size of fabric is needed for a net to cover
the box?
Top and Bottom 3x2 Small Ends 4x2 Sides 3x4
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The End
Mindi Luke