Thursday, April 17, 2008

Josephine's scribe post

How to find...
- Circumference of a circle
- Area of a circle
- Surface area of a cylinder
- Volume of a cylinder
Formulas:
Circumference of a circle - pi d (pi *d) OR pi 2 r (pi * 2 * r)
Area of a circle - pi r² (pi * r²)
Surface area of a cylinder -

area of circle = (pi * r²) * 2
+
area of square = H * C
=
surface area of a cylinder
Circumference = pi r 2 (pi * 2 * r) (also needed to find surface area of a cylinder)
Volume of a cylinder - area of the base * height

coming soon...:)

Tuesday, April 15, 2008

Rectangular Prism Test Scribe Q.1

VOL= area of base x height

BASE: lxw=

4x4=

16

HEIGHT= 4

16 x 4 = 64 cm3

SA= 2(hxl)+2(wxh)+2(lxw)=

SA= 2(16)+2(16)+2(16)=

SA= 32+32+32=

SA=96cm2

Monday, April 14, 2008

Karen's B.O.B

For Finding the Surface Area you just follow the fomula! 2(HxL) + 2(HxW) + 2(LxW)

Fomula:

Net of a Rectangular Prism:
Once you know the formula you can start filling in what you know.

Finding the Volume of a Rectangular is too. You just have to follow the fomula.

Formula:

Now we can answer the fomula! By filling in the information we know!

gails bob

BOB - blogging on blog

AREA:

Volume:

Israelie's BOB

Surface Area of a Rectangular Prism

---H=2 W=2 L=4---

SA=2(HxL)+2(HxW)+2(LxW)

=2(2x2)+2(2x2)+2(4x2)

=2(4)+2(4)+2(8)

= 8+8+16

= 32 cm²

Volume of a Rectangular Prism

---L=5 H=2 W=2---

V= LxHxW
= 5cm x 2cm x 2cm
= 20cm³

OR

area of the base x height
=10cm x 2cm
= 20cm³

:)

Kathleens B.O.B

Surface area of a rectangle prism:

A way to solve this problem:

L= 12

W= 4
H=12

Formula:
surface area(sa) = 2(hxl) + 2(hxw) + 2(lxw)
sa= 2(12x12) + 2(12x4) + 2(12x4)
sa= 2(144) + 2(48) + 2(48)
sa= 288 + 96 + 96
sa= 480 cm sqaured

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

Volume of a rectangular prism:

Formula:

Erick's BOB

First Up Surface Area.!

Now the Area of a rectangular Prism is the area of all of the sides of the shape added up.

This is the net. This gives you a very good visual aid in helping you find the surface area of the shape because it shows all of the sides and squares.
Also it just looks neater.

How to find the Surface Area.

Ok. so, shown on this net we have each side measuring 5cm. Now i did some work that is not shown here, but all i did was get the area of the box by using the formula, LxW. So 5x5 would give me the area of one square.

Now all we need to do is use a simple formula to find the surface Area.

Here's the formula for that!

Surface Area= 2(hxl)+2(hxw)+2(lxw)

Surface Area=2(5x5)+2(
5x5)+2(5x5)
Surface Area=2(25)+
2(25)+2(25)
Surface Area= 50 + 50 + 50
Surface Area = 150cm2

Now its Time for the Volume!!

Now Volume is really simple! All you have to do is Get the measurements of all three sides and multiply them using this formula.
Volume of a Rectangular Prism
LxWxH

5cm2x5cm2x5cm2=125cm3

Another way is Area of base X Height

(25cm2)5cm2=125cm2

Josephine's B.O.B

Surface area of a rectangular prism:

L=6cm
W=2cm
H=2cm
SA = 2(H * L) + 2(H * W) + 2(L * W)
= 2(2 * 6) + 2(2 * 2) + 2(6 * 2)
= 2 * 12 + 2 * 4 + 2 * 12
= 24 + 8 + 24
= 56cm²

click for bigger picture

Volume of a rectangular prism:

L=4cm
W=2cm
H=2cm
V = (L* W) * H
= (4 * 2) * 2
= 8 * 2 = 16cm³
OR
= (area of the base) * H
= 8 * 2

= 16cm³

click for bigger picture

Exequelle's BOB

Surface Area of A Rectangular Prism
The surface area is the area of all the sides added up, how much area the object has.
A net is how an object would look if it was flattened. It would look like this. From a rectangular prism into its net.

Now to answer the question you have to use the formula:
2(W*H)+ 2(H*L) + 2(L*W)= The surface Area.
W= 8cm2
L = 4cm2
H = 1cm2

Basically you just fill in the all of the blanks.

2(W*H)+ 2(H*L) + 2(L*W) =
2(8cm2 x 1cm2) + 2(1cm2 x 4cm2) + 2(4cm2 x 8cm2) =
2(8cm2) + 2(4cm2) + 2 (32cm2) =
16cm2 + 8cm2 + 64cm2 =
Surface Area = 88cm2
Another way is to add up all of the areas of each rectangle in the net:
32cm2 + 32cm2 + 8cm2 + 8 cm2 + 4cm2 + 4cm2 =88cm2

Volume of a Rectangular Prism
Volume is how much space the object takes up.
The formula to find the volume of a rectangular prism is:
(W x L) x H = Volume
W = 8
L = 4
H = 1
Again you plug in the numbers.
(W x L) x H = Volume
(8 x 4) x 1cm =
(32) x 1 =
Volume = 32cm3
Another way to do this is B x H. If you didn't know the base is Width x Length.
Base = 32 Height = 1 32 x 1 = 32cm3

alicia's BOB

SURFACE AREA OF A RECTANGULAR PRISM
how to find it...
SA=2(hxl)+2(hxw)+2(lxw)
front sides top
and and
back bottom
SA=2(5x5)+2(5x10)+2(5x10)
SA=2(25)+2(50)+2(50)
SA=50+100+100
SA=250cm(sq)

VOLUME OF A RECTANGULAR PRISM
how to find it...
volume=area of base x height
base=5x10=50cm
height=5cm
50x5=250cm(cubed)

Jordan's BOB

The Surface Area Of A Rectangular Prism!

Surface area
is all
of the areas on all of the sides added up on a solid figure such as ( in our case) a rectangular prism.

This is called a net. --------------------->
Nets are made out of shapes like this cube.
This is how you would change a cube into a net:
Heres how to get the surface area of a rectangular prism:

We know that there are two 6cm squared, two 2cm squared and two 3cm squared.
This is what it looks like: ( don't forget the formula)

2(6cm squared) + 2 (6cm squared) + 2 (3cm squared) Now do some math
36cm squared + 4cm squared + 9cm squared =
49cm squared.

A longer way to do it is like this:

(6x6) + (2x2) + (3x3)
36 + 4 + 9 =
49cm squared.

Volume Of A Rectangular Prism

Lets say that we are trying to find the volume of a rectangular prism.

L = 6
W = 2
H =2

Here's how you solve it.

L x W x H = (6cm squared x 2cm squared) x 2 cm squared =
24 cm squared.

Multiple methods to show this are

Length x width x height ( height also known as depth)
or you could use
Area of base x height

B.O.B

SURFACE AREA OF A RECTANGULAR PRISM:
example:

W=2
H=2
L=4
SURFACE AREA formula for RECTANGULAR PRISM:

SA=2(H*L)+2(H*W)+2(L*W)
SA=2(2*4)+2(2*2)+2(4*2)
SA=2(8)+2(4)+2(8)
SA=16+8+16
SA=40 cm ²

VOLUME OF A RECANGULAR PRISM:

VOLUME formula for a RECTANGULAR PRISM:
L*W*H
(2*4)*4-32 cm²

Charmaines B.O.B

Rectangular Prism: Volume and Surface Area
In my B.O.B we are going to find out the
volume and the surface area of this
rectangular prism.

Surface Area
Here is my formula for my rectangular
prism.
2 ( 4 x 2 )+ 2 ( 1 x 2 )+ 2 ( 4 x 1 ) =
2 (8 cm2 ) +2 ( 2 cm2 ) + 2 ( 4cm2 ) =
16 cm2 + 4cm2 + 8cm2 = 28 cm2
The second way in finding the surface
area.
2cm 2 + 2cm2 + 4 cm2 + 4 cm2 + 8cm2
+ 8 cm 2 = 28 cm2

Volume
Now here is the volume for my rectangular
prism.
( L x W ) x H = area or you can also use.......
Area of the base x height
Formula :
( L x W ) x
H = area
L = 8
W = 4
( L x W ) x H H = 1
( 8 x 4 ) x 1 =32 x 1 = 32 cm3
Or the other way is
Area of the base x height = area of a rectangular
prism. The area of our base is 32 and 32 x our
height would be 32 x 1= 32 cm 3.

Kevin's BOB

In this B.O.B. we are going to find out how
to find the volume and the surface area of
a rectangular prism.

What we did was draw a net of our shape out on gird paper and each cube represents 1 cm and then we labled it. Make sure the formula is writen down. The formula is ....

2 ( 4 x 2 )+ 2 ( 1 x 2 )+ 2 ( 4 x 1 ) =

2 (8 cm2 ) +2 ( 2 cm2 ) + 2 ( 4cm2 ) =

16 cm2 + 4cm2 + 8cm2 = 28 cm2

A secccond way is to just add the lengths together like this... 2cm 2 + 2cm2 + 4 cm2 + 4 cm2 + 8cm2 + 8 cm 2 = 28 cm2

To find the area of a rectangular prism you can use 2 diffrent stratigies or formulas. You can use...

( L x W ) x H = area or you can also use....... Area of the base x height. in this B.O.B we are going to solve it using both. First we drew a net of the rectangular prism.

Fromula : ( L x W ) x H = area

L = 8
W = 4 ( L x W ) x H
H = 1 ( 8 x 4 ) x 1 =

32 x 1 = 32 cm 3

The seccond way to solve this equation is to use the formula >>>>>> Area of the base x height = area of a rectangular prism.

The area of our base is 32 and 32 x our height would be 32 x 1= 32 cm 3. Since we are dealing with a 3 dimensional shape we have to make sure we use cubed witch is 3 instead of 2.

Judy's BOB

THE SURFACE AREA OF A RECTANGULAR PRISM
1.what is surface area?
surface area is the total area of the outside of a 3-D shape

2. how do you find the surface area?

first take your shape, and draw what it
would look like if it were opened and laid out:

Then measure the sides,
and find the area of each separate square (or rectangle)
.... suppose the sides are all 2cm long.
The formula to find the area of a square is
Length x Width so the area of each square would be 4cm²

Finally, use the formula to find the surface area.

you can either use:

(area = a)
a+a+a+a+a+a= surface area

4cm²+4cm²+4cm²+4cm²+4cm²+4cm²= 24cm²
OR
2 (HxL)+ 2(HxW)+ 2(LxW)
2(2x2)+ 2(2x2)+ 2(2x2)
2(4)+2(4)+2(4)=
8cm+8cm+8cm= 24cm²
------------------------------------------------------------------------------------------------
THE VOLUME OF A RECTANGULAR PRISM

1. what is volume?
the amount of space an object takes up. in this case, a rectangular prism

2. How do you find the volume?

take a rectangular prism, and measure
it's length, width, and depth (also called height)

Then use the formula to find out the volume. You can use:

length x width x depth
3cm x 5cm x 2 cm
=30cm
³
OR
Area of base x depth
(3cm x 5cm) x 2cm
15cm
² x 2cm= 30cm³