## Tuesday, October 4, 2011

### Brandon's Math Post

Today in class we reviewed on how to find a cylinder with a piece in the middle.

How to find the TSA of this object

TSA
= Large cylinder - small circles + cylinder
= 2πr^2 + 2πrh - 2πr^2 + 2
πrh
= 2π4^2 + 2π4(20 - 2π3^2 + 2π3(20)
= 2
π16 + 2π80 - 2π9 + 2π60
= 32
π + 160π - 18π + 120 π
= 294
πm^2

The height of this triangular prism is 8m, the base is 6m and the length it 10m
Tile it with 10x20cm tiles. How many tiles are there?
So what I did is:

a^2+b^2 =c^2
8^2+3^2 = c^2
64+9 = c^2
73 =c

square root 73 = square root c^2

8.54 = c

SA roof = lw
= (8.54x10)
= (85.4)
= 170.8m^2

Tile = 10 . 20
= 200cm^2

lm^2 = 100cm x 100cm
= (100 cm)^2
= 10 000 cm^2

170.8 x 10 000

1708000 cm^2 / 200 cm^2 = 8540

I will need 8540 tiles.

The third and final figure.

Tiles are 15 x 30 cm, how many tiles are there?

a^2 + b^2 = c^2
4^2 + 2.5 = c^2
16 + 2.5 = c^2
22.25 = c^2
square root 22.25 = square root c^2
4.72=c

SA roof = l w
= 4.75 x 8
= 37.76
= 75.52 cm^2

S.A = 9x(s^2) 8(4^2)
= # (face(s^2) 8(16)
= 9(3^2) 128 cm^2
= 9(9)
=81 cm^2

S.A = top + 4 sides
= s^2 + 4 (lxw)
= 2^2+ 4(2) (3)
= 4+4(10)
= 44 cm^2

HOMEWORK
Workbook + textbook + Vocabulary + Test review,
Practice sheets

Ivan will be doing the next blog.

P.S. Sorry for the small pictures.

1. Good job on your post Brandon! I liked how you highlighted the key words and how you showed the formula and showed the work step by step. But you shouldve also explained how and why you got your answer, for example, why you put 3^2 instead of 6^2, explain why you halfed it.. Also edit to make the pictures larger and add videos & links. Good job for reminding us what hw was, keep up the good work! :D

2. Great job Brandon! Your scribe was definitely neat and easy to understand. Not only that, but it is very organized. I liked how you highlighted key words and added pictures to explain your point. You explained how to get answers to surface area questions very well. Although, you should add a video & link if possible. Overall, you did a good job!

3. Great Job Brandon. I like how you have a picture to further explain on how to get a TSA of a shape. Also I like how your explanation is detailed.Next time you should probably include a picture for the last formulas and on how to type the pie and squared sign is on my comment on John's post.

4. Good job Brandon. I liked how your post was neat and that the pictures showed the dimensions in detail. You also highlighted the keywords which was helpful. But, I suggest you bold some of the key things needed and try finding either a link or video. Overall good job!

5. Good job, Brandon. I liked how you did your blog post. You highlighted all the keywords. Although next time Try to make your pictures a lot bigger.

6. Good job Brandon! Your blog was really easy to understand because everything was organized and I really like how you made keywords and highlighted many things. The pictures helped understand the problem more, but they were a bit small. You should add a link or a video like what other people said.

7. Good Job on your post Brandon! I liked how you added pictures and coloured the words to show what's more important. But try to crop what's not used in the picture. Overall, keep it up! :)

8. Great job Brandon! I liked how you highlighted the important components. It was also easy to understand and I like you pictures, but next time don't leave such a big space after and make it a little bit bigger. Other than that, great job.

9. Great job Brandon! You used colors to highlight all the important words and it was very neat and organized. Great job on your first scribe!