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Wednesday, September 28, 2011

John Chua's Blog Post

Today in math class we learned how to find the surface area of 3D shapes with missing pieces and find an area of a cylinder by solving it in pi.

first shape look like this:
top bottom rest of shape extra piece
S.A.= 2 (lw) + Ph(perimeter-height)+ 2(lw)

to find the perimeter of the rest of the piece is 3+2+3+2.
the extra piece that is not shown. It has two pieces that has a dimension of 1-1.

2nd shape:

top and bottom sides front back inside
S.A.= 2(lw) + 2(lw) +2(s2+s2) +4 (lw)
= 2(2)(3) + 2(2)(3) +2 (3^2-1^2)+4 (1)(2)
= 12+12+2(9-1) +8
= 48^2

3rd shape is a cylinder:

here is the net of the image:

Circumference= (pi.D)---->(2 pi r)

diameter of the circle is 10 and the height of the cylinder is 12.

S.A.=2 pi r^2 + 2 pi r h ( to find the radius you divide the diameter by 2)
=2 pi 5^2 + 2 pi (5)(12)
=2 pi 25 + 2 pi 60
=50 pi + 120 pi
= 170u^2 <------ solve in pi (accurate)
= 534.07 u^2 <------- solve to the hundredths (approximation)

HOMEWORK!! : Journal, all apply 1.3(22 or 23), all practice sheet , all workbook, Study for test( Tuesday or Wednesday)

Aj will be doing the next blog.


  1. Good job, John! I really like you added pictures, and in the pictures you showed the missing piece in the shape. I think for next time you should check over your post, cause I found some errors like, "Ph (perimeter-height" it looks like you're trying to say perimeter subtract height, when it's perimeter multiplied by height. You also forgot to add "u^2" on the answer for the 2nd shape. I like how you added all of the homework and reminding us about the test next week. Also how you added all the notes from today. Keep it up!

  2. Great job John! Your information is organized in a manner that is clear to read. Your pictures are clear but your formula's are a bit wrong. Also your blog seems plain, I suggest adding colour or bolding some phrases that are important. You did a nice job and your homework reminder is intriguing. Next time I highly suggest adding a link or a video. Overall fantastic first blog, and keep up the good work!

  3. Good job John! Your pictures were good, easy to look at! I thought the way you showed your equation was kind of all over the place, so it was hard to look at for me. You should use colours to make key words stand out. But other than that. Good job!

  4. Good Job John. I like how you explained how to figure out the surface area of the shape. Also you added some other information with a picture to make it more detailed. Next time though i recommend you use the word box in paint were you can just type the labels. Also here is what you can use for the squared ² (alt + 253) and pi ╥ (alt + 210). Good Job

  5. Good Job on your first post John! It was decent but could get better. For the pictures you could have added what the length/height/base in the picture. But it's all good. Good job,

  6. Good job, John! I like how you added in the formulas, plus the pictures helped too. Though, next time you should bold in and colour the important words for it to stand out. Overall, you did a wonderful post. Keep it up!

  7. Good job john. Good job on including the formulas and showed how you got the answers. Good job including pictures, but next time make some of the pictures larger and more clear. Also, i like how you included what was for hw. Keep it up!

  8. Great job John! You did a great job on adding the formulas but I think they should be aligned so it's easier to read. Your pictures were also very neat and easy to read. I think you should have added some colors to important words. Keep up the great work John.