Saturday, April 19, 2008
Thursday, April 17, 2008
- The circumference(c) of a circle is the distance around the circle.
c = 2πr
- The radius (r) of a circle is the distance from the center of the circle to the outside.
- The diameter(d) of a circle is the length of half of the circle or twice the length of the radius.
- π or pi is a constant and is approximately equal to 3.14
Radius: d / 2
Diameter: 2 x r
Circumference: 2 x π x r
Area of a Circle:
Radius² - Area of a circle
- Area of circle = πr²
π (Pi) - 3.14
The Area - (3.14)(r²)
Surface Area of a Cylinder:
Volume of a Cylinder:
Volume = Area of base x height
Tuesday, April 15, 2008
Surface Area Of a Rectangular Prism
surface area is the total amount of area a whole 3D shape contains.
formula: area front + area back+area side+ area side2+area top+area top+area bottom.
area front + area back = L x W
area side + area side2 = W x H
area top+ area bottom = L x H
SA = area front + area back+area side+ area side2+area top+area top+area bottom. SA= 2 (L x W) + 2(W x H) + 2 (Hx L)
SA= 2 (4cm ² x2cm ²) + 2 (4 cm ² x 2 cm ²) + 2( 2cm ² x 2cm ²)
SA= 2 (8cm ²) + 2 (8 cm ²) + 2 (4 cm ²)
SA= 16cm ²+16cm ²+8cm ²
SA= 40 cm ²
looks complicated ? REALLY ITS NOT :)
volume of a rectangular prism
V=(L X W) x H
V= (17cm ² x 11 cm ²) x 1 cm ²
V= 187 cm ² x 1cm ²
Volume is the amount of space an object takes up.
FORMULA: LxWxH= volume³
Monday, April 14, 2008
Volume is how much the entire shape takes up. To get the volume of a rectangular prism, you multiply the length (L), width (W), and height (H). That will get you the volume of the entire shape. The answer, is always cubed or in 3. ex. 18 cubic(3) centimeters.
To find out the Surface area of a Rectangular Prism the first thing you have to do is make your object into a net so it looks like this:
(Surface Area : Surface area is the measure of how much exposed area an object has)
After Laying out your Rectangular Prism into a net you have to find the area of each shape. So to find the surface area of the whole object you have to find the area of each shape and add them together like this:
The Front and back Area = 8 x 4 = 32 cm ²
The Sides Area = 8 x 4 = 32 cm ²
The Bottom and the Top Area = 4 x 2 = 8 cm ²
Then you multiply each one by two becuase there are two of the same shape. It makes things easier.
32 x 2 = 64
32 x 2 = 64
8 x 2 = 16
Then you add all of those up and that gives you your surface area!
64 + 64 + 16 = 144 cm ²
Finding the Volume of a Rectangular Prism
To find the Volume of a Rectangular Prism is quit simple all you got to do is follow this formula:
Length x Width x Height = Volume
(Definition of Volume: The amount of space, measured in cubic units, that an object or substance occupies)
Now all you got to do is plunk in your numbers and do the math
Height x Length x Width = Volume
10 cm x 6 cm x 4 cm = 240 cm ³
(Since it is a three dimensional object we put cubed or ³)
Thats all you have to do :)
I learned to get the surface area of a 3 dimensional shape. Lets say you have a rectangular prism, you first need to make the prism into a net. Now you have to find the front area, the back area, the top area, the bottom area, and both of the sides areas. The easier way is to find the area of the top area then double it, then double the area of the top area and find the area of one side then double it since theres two of everything. So it would look like this,
I learned to get the volume you need the formula L x w x h = v. For example if you had a book flat on the table with the length=18 cm, the width=21, and the height=6 you would use this formula.
It is cm3 (or cubed) because it is a 3 dimensional shape.
Surface area is the area of the surface on a rectangular prism .
Surface area = Length x height
= 2cm x 2cm = 4squaredcm
= 4squaredcm x 2 = 8squarecm
= 6cm x 2cm = 12squarecm
= 12squarecm x 4 = 48squarecm
Surface area = 48squarecm
The volume of a rectangular prism is how much space it takes up .
Volume of rp = length x width x height
length = 6cm
width = 2cm > 6 x 2 x 2 = 24squarecm *
height = 2cm
Volume of rp = 24squarecm
Surface Area = 3 + 3 + 3 + 3 + 3 + 3 = 24 cm2
The surface area is the area of the outside part of a shape. For a rectangular prism it would be the 2 sides, the top and bottom, and the front and back. A net is an easy way to show the rectangular prism's area .
The formula for this would be :
surface area = area top + area bottom + area side + area side² + area front + area back
surface area = 2(L x W) + 2(H x L) + 2(H x W)
= 2(4cm x 2cm) + 2(2cm x 4cm) + 2(2cm x 2cm)
= 2(8cm) + 2(8cm) + 2(4cm)
= 16cm² + 16cm² + 8cm²
= 40 cm²
You can use the formula examples i showed you here to help you answer your own surface area question.
The volume is the measurement of how much space the shape takes up. The answer is always cubed or in an exponent ³.The volume of a rectangular prism would look like this.
The formula for this would be:
volume = L x W x H
= 3cm x 2cm x 2cm
= 12 cm³
volume = area of base x height
= 6cm² x 2cm
Surface Area of a Rectangular Prism:
Surface area is the total area of the prism. The measurements from the net all added up.
Surface Area = lengthxheight
= 4 cm x 4cm = 16cm(2)
=8cmx4cm=32 cm (2)
Then you add them all up.
Volume of a Rectangular Prism:
8x4x16 = 512 cm (2)
base = 96cm(2) ( you add up the three rectangles across the middle )
height = 16 cm(2)
96x16 - 1536
Volume = 1536 cm (2)
Thursday, April 10, 2008
Tuesday, April 8, 2008
My First Shape :
My Next Shape Was :
My Final Shape Was:
Those were the shapes I had to do for the scribe. Sorry I didn't post this earlier.
Monday, April 7, 2008
He thought us how to do find the area of the shape.
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