## Friday, March 9, 2012

### Tinille's Surface Area and Volume Post

What is a Prism:

- A prism is three dimensional geometric shape.

- ends have the same size or shape

What is a Surface Area:

- measures the combined area of all the surfaces of a 3D shape.

• Rectangular Prism

NET:

WORK:

How to get the answer for finding Rectangle's Surface Area:

Step 1: Find the top, front and side length and width of the rectangles.

Step 2: Multiply the length and with of the 3 sides using the formula l x w = area.

Step 3: After finding the area of each sides, you have to use the formula TSA= 2(T+F+S) to find the total area of the rectangular prism.

NOTE: We are multiplying the total of top, front and side because there are 6 pieces in a rectangular prisms. Top and Bottom are the same so as Front/Back and Side/Side.

• Triangular Prism

NET:

WORK:

How to get the Total Surface Area of a Triangular Prism:

Step 1: Find the 3 rectangles and their lengths and widths.

Step 2: Using the formula l x w= area. Multiply the length and width for each rectangle to get their areas.

Step 3: Then, we have to find the base and height for the 2 identical triangles.

Step 4: Using the formula, bxh/2 (base multiply height divided by 2). Multiply the base and the height. Then after multiplying the base and height. You need to divide it by 2 to get the area of the 2 identical triangles.

Step 5: After finding all the areas of the 5 sides in a triangle. You need to add all of the 5 areas to able to find the Total Surface Area of the triangular prism.

• Cylinder

NET:

WORK:

Formulas that will help you to be successful in finding the TSA of a cylinder :

: TSA= 2(π x r2 ) + (π x d x h)

: To find the radius: r=d/2 (diameter divided by 2)

: To find the diameter: d= 2r (2 multiply the radius)

: To find the area of the circle: circle= πr 2

: To find the width for the rectangle: circumference= πd

: To find the area of the whole rectangle: l x w = area (length multiply width)

• Here is a GAME for you to play and practice before the test on March 12.

I hope I helped you in this scribe post. Also, I hope you'll memorize all the formulas so you can be successful. :D
• I would greatly appreciate if you comment below on where I could improve on and I did something wrong so I could change it as soon as possible. :)

• PLAY MANGA HIGH! GOOD LUCK!

-------------------------------------------------------------------------------------------------

Volume of Prisms
What is a volume?
- a meat cutter and it uses spaces for measurement.

• Triangular Prism

Rectangular Prism

Prism with a FRACTION

Cylinder

To be able to find the VOLUME of a prism, you need to remember all the formulas in order to get the right answer. These are the formulas for each prisms:

Triangular Prism: Rectangular Prism: Cylinder:

v= (bxh1/2) x h 2 v= l x w x h v= (πr 2) x h

NOTE: In addition to that, If you're finding the shaded part of the prism and the fraction is given. Divide the fraction and if its an UGLY decimal, you have to divide the answer to the fraction's denominator and multiply it from the numerator. BUT. If the decimal is NOT ugly, you have to multiply the decimal and the answer to be able to get the right answer fort he shaded part.