## Saturday, March 10, 2012

### Angela's Surface Area and Volume Post

*click on the images to enlarge*

How to find the Total Surface Area of a Rectangular Prism:

Method 1:

Step 1
: Find the areas of all the rectangles, FRONT, SIDE, and TOP.

• Finding the area of the TOP rectangle:
Dimensions:
l = 5m
w = 10 m

l x w = area
5 x 10 = area
50m2 = area

• Finding the area of the FRONT rectangle:
Dimensions:
l = 6m
w= 10m

l x w = area
6 x 10 = area
60m2 = area

• Finding the area of the SIDE rectangle:
Dimensions:
l = 6m
w= 5m

l x w = area
6 x 5 = area
30m2 = area

Step 2: After you've found the area of the three rectangles you add them all up together:

50m2+60m2+30m2= 140m2

Step 3: After you've added all three sides you need to multiply the answer by 2:

140m2x 2 =SA
280m2 = SA

METHOD 2:
Step 1: Draw the NET of the rectangular Prism.

Step 2: Find the Area of the Lateral area:
To do this you need to....
Find the length by adding up the lengths of the rectangles:
6 + 5 + 6 + 5 = 22 m
l x w = LA
22 x 10 = LA
220m2= LA

Step 3: Find the area of the other 2 identical rectangles:
l x w = a
6 x 5 = a
30m2= a

Step 4: Add up all the areas:
SA= LA+2(l x w)
SA= 220+2(5 x 6)
SA= 220+2(30)
SA= 220+60
SA=280m2

How to find the Total Surface Area of Triangular Prisms:

How to find the Total Surface Area of Cylinder:

Here's also a video:

Don't forget to play the new Manga High Challenges!:

Finding the Volume of a Rectangular Prism:

Finding the Volume of a Cylinder:

Finding the Volume of a Triangular Prism:

Here are some games that will enable you onto practicing on finding the volume of a shape: