Finding volume and surface area and/or finding missing parts given volume and/or surface area.

1. Volume and Surface Area of Geometric Solids and finding Missing Parts
Skills15 and 16
These lessons use formulas from the formula page to find the volume (how much the
figure holds) and/or the surface area (how much material you need to cover the figure).
To begin with we should become familiar with the names of the figures. Many of these
are commonly found at the grocery store as containers. Sometimes this will help take away
the difficulty of the problems. Use pages 99 and following from your book.

2. A rectangular solid is like a cracker box or cereal box. A cylinder is just a
soup can. A cube is like a sugar cube. A prism is just some kind of box
with a top and bottom. One shape you should pay attention to is the
triangular prism. It occurs on several practice tests and is usually lying
down on its side. The height is along the side from the top to the
bottom which are at the front and back of the figure.
Most of these problem just require putting numbers from the figure into the formula
from the formula page. Look at your own formula page. The part below is too hard to read.
However, you can see the part you need to find on the formula page. If you need a formula
Page, go to https://ged.com/wp-content/uploads/math_formula_sheet.pdf

4. I have worked out many problems from pages 101 and 102 by showing my work
on page 102a. See below and in your book. Here are #2, 3, 6, and 9 volumes.
Remember to put 3.14 for π (this is on the formula page).

5. Here are surface area problems from page 102. I have done #2,3,and 8. Surface area
is a little harder but not as likely as volume to be on the test. Just plug in the formula.

6. Sometimes the test will have problems that don’t ask you to find the volume or find
the surface area. Rather, the problem will give the volume or surface area and ask you to
find some other part or the formula that is missing. I wrote out several sample problems on
Pages 104a and 104b. Below see some Volume problems.
Skill 16 Missing Dimensions (parts of the figure)

7. More volume problems form page 104a

8. Surface Area problems with missing sides. Page 104b.

9. More Surface Area problems with missing parts form page 104b.
Note that a sphere is like a basketball or globe. It has a radius, r, like a circle.

10. This is the last geometry lesson!! As you can see, there really is not much
Geometry on the test. The last few lessons are about data and statistics.