873 Math Blog (2011): scribe post

Showing posts with label scribe post. Show all posts

Monday, March 12, 2012

Lance's Surface Area And Volume Post

Rectangular prism

l*w*h=v                   1/3 Full   300/3=100
10*5*6=v                               100cm³
300cm³

Triangular Prism                          b*h/2    9*8/2=36    36*5= 180cm³ 2/4 full
180/4=45   45*2=90cm³

Cylinder
πr² 3.14*12*12 5/10 full 452.16/10=45.22 45.22*5=226.1cm³
452.16cm³

Sunday, March 11, 2012

Cyerra's Surface Area Post

Cylinder

Triangular Prism

Rectangular Prism

Cylinder Volume

Radius = 5 cm
Height = 23 cm
3.14 x 5 x 5 = 78.5
78.5 x 23 = 1805.5 cm

Rectangular Volume

L x W x H
1 x 3 = 3
3 x 5 = 15

Triangular Volume

7 x 7 = 49
49 / 2 = 24.5
24.5 x 12 = 294

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

Find 3 fifths:
294 / 5 = 58.8
58.8 x 3 = 176.4

Kim's Surface Area Post and Volume Post

Surface Area

Surface Area definition: The total area of the surface of a three-dimensional object.

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Rectangular Prism:

Solution:

Top:

( length = 5m ; width = 10m )

a = l x w

a= 5 x 10

a= 50m

Front:

( length = 6m ; width = 10m )

a= l x w

a = 6 x 10

a= 60m

Side:

( length = 6m ; width = 5m )

a= l x w

a = 6 x 5

a= 30m

Total Surface Area Formula:

TSA = 2( T + F + S)

= 2( 50m + 60m + 30m )

= 2( 140m )

= 280m²

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Triangular Prism:

Solution:

Rectangles

Rectangle 1:

( length = 9cm ; width = 5cm )

a = l x w

a = 9 x 5

a = 45cm²

Rectangle 2:

( length = 10cm ; width = 5cm )

a = l x w

a = 10 x 5

a= 50cm²

Rectangle 3:

( length = 8cm ; width = 5cm )
a = l x w
a = 8 x 5

a = 40m²

Triangles

( base = 8cm ; height = 9cm )

a = b x h

------

a = 8 x 9

------

a = 72

------

a = 36cm²

TSA = 50cm + 45cm + 40cm + 36cm + 36cm

= 207cm²

^----------

Cylinder:

First Way:

Circles:

r = d

---

r = 8mm

-----

r = 4mm

Circumference:

c = π d

c = 3. 14 x 8

c= 25. 12mm

Lateral Area:

length x width

25.12 x 12

= 301. 44mm2

Area of circle

Area of circle = π r²

= 3.14 x 4²

= 3.14 x 16

= 50.24cm²

TSA = 301.44mm + 50.24mm + 50.24mm

= 401.92mm²

Second Way

l = 12mm ; d = 8mm

r = d

----

r = 8mm

------

r = 4mm

SA = 2 (3.14 x 4² ) + (3.14 x 8 x 12)

SA = 2 (π r2)+ (π d h)

SA = 2 (50.24) + (301.44)

SA = 401.92 mm²

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Here is a helpful link for a better understanding of Surface Area.
Here is a helpful video for the formula of a Triangular Prism:

Volume:

Triangular Prism:

V = (b x h ÷ 2) x h
V = (3 x 4 ÷ 2) x 8.5
V = 7.5 x 8.5
V = 63.75 m³

Rectangular Prism:

V = l x w x h
V = 20 x 80 x 16
V = 25600 cm³

Triangular Prism with fraction:

V = (b x h ÷ 2) x h

V = (8 x 4 ÷ 2) x 6.5
V = 16 x 6.5
V = 104 cm³

Cylinder:

r = d ÷ 2
r = 12 ÷ 2
r = 6cm

V = π x r² x h
V = 3.14 x 6² x 15
V = 1695.6 cm³

Friday, March 9, 2012

Jennifer's Surface Area and Volume Post

Rectangular Prism

Triangular Prism

Cylinder

VOLUME

Triangular Prism

Rectangular Prism

Triangular Prism with a Fraction

Cylinder

I hope this video helps!

*The only one it doesn't have is a cylinder!

Monday, February 13, 2012

Lance's Texbook Scribe Post (4,10,15) Pythagorean

4) Estimate the square root of each number, to one decimal. Check with a calculator.

a) 72 b) 103 c) 55

10. Kai uses an entire can of paint on a square backdrop for the school play. The label on the can states that one can cover 27 m² of wall surface. Estimate the backdrop's side length, to one decimal place.

5x5=25 and 6x6=36 so it should be between the numbers 5 and 6.

5.2x5.2=27.04 then it move it up into one decimal place which is 5.3

15. Order the following numbers from least to greatest: 7, square root of 46, 5.8, square root of 27, and 6.3.

5.1, 5.8, 6.3, 6.7, 7

1) Answer in a short paragraph with diagrams