Tuesday, February 15, 2011

Math textbook: pg. 250-253 #2,5,8,10

No, it does not matter.
Take this rectangular prism for example (the proportions are probably strange, but you get the idea.)

v=area of base x height
v=50cm² x 4cm

v=area of base x height
v=20cm² x 10cm
As you can see the volume is the same.

v= area of base x height
v=12cm² x 5cm

v= are of base x height
v= 15cm² x 4cm

v= are of base x height
v=120cm² x 8cm

v=are of base x height
v=48cm² x 20cm

So, basically one centimeter cube would look like this:

And if you were to make one layer or a base out of the fifteen centimeter cubes used, it should look like this:

The area of the top of this one layer should be 15cm² so we will use that as our base.

Since the prism is made of 5 layers of those 15 centimeter cubes we will use that as our height.

v= area of base x height
v= 15cm² x 5cm

Though worded differently it is basically asking for it's volume.

v= area of base x height
v= 1250cm² x 100cm
v= 125 000cm³

Here's a link to calculating volume.

And two videos explaining both rectangular prisms and cylinders:

Cylinder Volume and Volume Problems

v=π x r x r x h
v=(3.14 x 12 x 12) x 15
v= 452.16cm^2 x 15 cm
v= 6782.4 cm^3

6782.4/4= 1695.6cm^3

Assume that 1/4 of the cheese was cut.

Cylinder one:
r= d/2
r =10/2
r= 5m

v= π x r x r x h
v= (3.15 x 5 x 5) x 30
v= 78.5 m^2 x 30m
v= 2355m^3

Cylinder two:
r= d/2
r= 8/2

π x r x r
(3.14 x 4 x 4)
50.24 m^2

2335m^3/ 50.24m^2= 46.5 m

I pray that I made any sense.


  1. Mrs.Anabelle M. Salonga a.k.a. Miss. Perfect has another perfect blog post! I liked the helpful videos, but next time use a ruler to make the prisms so that it looks more crisp.

  2. Great Job Anabelle. Your post was verl neat and organized. Each question is explained in great details. Also your links and video would relly help.

  3. Great job Anabelle. I liked that you drew your own pictures. I also liked how you used a different color for the answer. Your post looked very neat and organized. Great job and keep up the good work.