## Friday, March 9, 2012

### Nicole's Surface Area and Volume Post

Rectangular Prism :

Solution :

Top: 10m ad 5 m 2
Front: 10m and 6 m
Side: 5m and 6 m

To get the (TSA) of your rectangular prism you must multiple the two numbers you have from the top, front, side (Example : Top : 10m x 5m =
50m2 Front: 10m x 6m = 60 m2and Side: 5m x 6m = 30m2 ). When you're done multiplying the top, front and side you add up their sum (50+ 60+30=140m) then you multiple 140 by 2; you multiple it by 2 because we have 2 tops, 2 fronts and 2 sides (140x2=280mm²) 280m is your total surface area.

Diagram:

Work:

Triangular Prism:

Solution:

To find the area of a triangular prism you must first find the length and width of the three rectangles (Length: 5cm Width: 10cm, 9cm and 8cm) then you add up all the widths together which would get you 27cm, you take that 27cm and multiple it by the length, which is 5 (27 x 5= 135cm) Now you have the area of the three rectangles. To get the area of the two triangles you have to use the formula base x height divided by 2 (72 ÷ 2 = 36cm) Now you have to add 135 and 36 together but you have to add 36 on their twice because there are two triangles (135 + 36 + 36 = 207 cm²) 207cm² is the area of your triangular prism.

Diagram:

Work:

Cylinder:

Solution:

To figure our the area of a cylinder is pretty self-explanatory, but I'll explain how. Since they give you the diameter but, not the radius, you have to find the radius yourself. You do that by using a formula (diameter divided by 2 equals radius); (8 ÷ 2 = 4) so the radius is 4mm.Now that you have the a radius you can get started with the formula on how to get the area of the cylinder the ( Formula:TSA= 2(π x r2 ) + (π x d x h) ) Now you just have to fill in the formula with the correct numbers ( Formula: TSA= 2 (3.14 x 4²) + (3.14 x 8 x 12).

Diagram:

Work:

Volume Questions :

Triangular Prism:

Solution :

Rectangular Prism:

Solution:

Triangular Fraction Prism:

Solution:

Cylinder:

Solution: