Thursday, September 30, 2010
Then we did the went over one of the Show You Know on Page 29 on the math-book.
Question: What is the area of the surface that is against the ground? Explain your answer.
S.A = 80( 60 + 20+ 30 + 20 )
S.A = 10,400 cm
S.A = 2 [40 (60) + 20 (30) ]
S.A = 2 ( 2400 + 600 )
S.A = 2 (3000)
S.A = 6000 cm
Then you add 10,400 + 6000 which equals 16,400 cm2.
- Finish Check Your Understanding question 2 and 3.
- Do the ALL the apply and practice.
REMEMBER DUE ON MONDAY.
AND FOR THE NEXT PERSON I PICK TO DO THE BLOG IS,........... MICHELLE. (: TEHE.
Wednesday, September 29, 2010
Tuesday, September 28, 2010
To calculate the area of faces on a cylinder, you must use the formulas:
πr² (pi x radius squared) AND 2πrh (2 x pi x radius x height)
For finding the area of the top face of a cylinder you must use the formula:
The radius of the cylinder is 5cm
π r ²(pi x radius squared)
(3.14) (5²) I got 3.14 from pi, and 5 because that is the radius.
(3.14) (25) After squaring 5, you are left with 25.
After multiplying 3.14 and 25, the top face of a cylinder would be:
You also need to know the formula for finding the area of the rectangle in a cylinder. The formula for that is:
2πrh (2 x pi x radius x height)
A cylinder has a radius of 4, and a height of 3.
2 π r h (2 x pi x radius x height)
2x(3.14) (4) (3) 3.14 represents pi, 4 is the radius, and 3 was the height
(6.28) (4) (3) I got 6.28 after multiplying 3.14 by 2
(25.12) (3) 25.12 was from multiplying 6.28 by 4
75.36cm² is the area of the rectangular face on a cylinder
For finding the surface area of a prism, you will need the following formula:
2(lxw)+ 2(lxh)+ 2(hxw)
(You add the two because there are 3 pairs of opposite sides with the same area)
A prism has a length of 5, a height of 2, and a width of 3, what is the surface area?
To start off, you would need the formula:
2(lxw)+ 2(lxh)+ 2(hxw)
Then replace the variables with their numbers:
2(5x3)+ 2(5x2)+ 2(2x3)
One at a time you multiply the brackets:
2(15)+ 2(10)+ 2(6)
Once you've done that, you multiply the lengths by 2:
Then you find your answer!
Now that were done.. just kidding we have to learn volume now.
To find the volume of a prism, you must use the formula:
WxDxH (width x depth x height)
(though they might not always give you the exact numbers)
A prism has a width of 2, a depth of 2, and a height of 2.
Start of with your fancy formula:
Fill in the numbers:
8cm³(volume is always cubed)
Thank you for reading my scribe post which took 5 hours.
WANT MORE PRACTICE? VISIT THESE SITES www.shodor.org/interactive/activities/surfaceareaandvolume www.mathguide.com/lessons/SurfaceArea.html
PLAY MORE TUTPUP CHILDREN
I choose JERIC for the next scribe.. just kidding it's actually
Friday, September 24, 2010
Thursday, September 23, 2010
and Mr. Backe !
Today in math class the first thing we did was we were given a grid , an integer grid and we had to write numbers on the top and along the side and it was addition . It was a timed integer assignment. This is what the assignment looked like .
sorry if you can't really see the numbers . i tried my best .
Also in math , we talked about rotating an object around a point . Heres what it looks like
im sorry that its kind of hard to understand or see
Black Shape = Where we started
Black Line = Line of Reflection
Purple Shape= Where it ends when reflected
Red Shape = Where it ends once reflected and rotated around point J which is located on ( 0,-3)
Okay , this is a technique that i used ..
Lets start with reflection , say Point A . I counted diagonally to the Line Of Reflection and i got 2 and a half squares . So from the Line of Reflection , i counted diagonally 2 and a half sqaures . Thats what i did with all of the Points .
For the Rotation , i drew a 90 degree angle , as you can see it says 90 degrees in PURPLE . So i started with Point C' . i counted 2 spaces in between the Center of Rotation and Point C . For a 90 degree angle i counted up from the Center of Rotation two spaces . I did that for all Points as well .
Im sorry if you can't really understand my explanations , i make things difficult in my head so its really hard for me to explain how i get my answers .
GET YOUR INTEGER TEST SIGNED
INTEGER SHEETS ( DUE MONDAY )
STUDY FOR THE SYMMETRY TEST
WRITE IN YOUR JOURNALS EVErYDAY
PLUS THE WORK THAT HE ASSIGNED FROM THE BEGINNING
Tuesday, September 21, 2010
The second method is rotating the object by first picking a letter part of your firgure like A. Then from the center of rotation count horizontal toward the firgure, then count vertical to the figure, then rotate that mini kind of object the way you need to. This is the way i use because its pretty easy.
SORRY IF ITS HARD TO UNDERSTAND I TRYED MY BEST !
homework was Extend 24 and 25 (hard), Workbook 1.2, Extra Practice 1.2 if you missed it.
INTERGER TEST TOMMOROW. !!!!
JERICK YOUR NEXT .
Monday, September 20, 2010
Rotation symmetry just means how many times a polygon fits onto its self to complete one rotation.
This flower can fit 9 times to its self.
Then we had to find the angle of rotation. Since it has 9 rotation symmetry, we have to divide it by 360 degrees. The reason why its 360 degrees is because the polygon used on the example above is fully turned which makes 360 degrees.
We then drew rotations on our graphs. The rotation can be clockwise or counter clockwise.
I choose Alvin to do the next blog.