CPhill

I don't  know......I registered  so long ago that I don't  even remember  what  the proceedure is / was....sorry!!!

[ 41  +  48  + 63  + 74 ]  /  4   =     avg

Can you finish it   ????

6. A regulation-sized soccer ball is 23 cm in diameter. How much fabric is needed to cover the entire surface? Use π = 3.14 and round to the nearest hundredth.

Surface  area of sphere  = 

4 pi (d/2)^2   =

4 pi  ( 23/2)^2  =

4 (3.14) ( 11.5)^2   =   1661.06  cm^2

5. A spherical fishbowl has diameter 24 cm. To fill the fishbowl three-fourths full, about how many liters of water will you need? Give your answer to the nearest tenth. Use π = 3.14. (1000 cm3 = 1L)

(3/4) *(4/3) pi * (24/2)^3   =   pi * 12^3  =   3.14 * 1728  =  5425.92  cm^3

5425.92 / 1000  ≈     5.4  L

4.  A scoop of ice cream with radius 4cm is placed on an ice cream cone with radius 3cm and height 16 cm. Is the cone big enough to hold the ice cream if it melts?

Volume of  scoop =  (4/3) pi  *( 4)^3  =    265/3  pi  cm^3 

Volume of cone  =  (1/3)pi (3)^2 * 16  =  144 / 3  pi  cm^3

The  cone will not  hold  the scoop

1)

The  radius  of  the  circle will be  =

sqrt ( radius of sphere^2  - distance of the  plane  from  the  center of sphere^2 )  =

sqrt ( 5^2  - 3^2)  =  sqrt  (16)   = 4

So....the  area  of  tis circle =  pi * 4^2  =  16 pi   unts^2

See if  you can  do  (2)  and (3)  based  on this.....let  me  know  if  you  get  stuck

Angles  B  and C  are  supplementary

So

B +  C  =  180

B +  3B  =  180

4B  =  180

B  =180 / 4   =   45  ( degrees  )

m =  7

The  perimeter  of each successive  triangle  is   (1/2)  of  the previous triangle

Call the  perimeter  of  the  first  triangle  =  P

The  perimeter  of  the nth  triangle  is   P (1/2)^(n - 1)

So...the perimeter of  of  the 10th triangle  is   P(1/2)*(10-1)  =  P(1/2)^9

The perimeter of the 3rd  triangle is  P(1/2)^(3 - 1)  = P(1/2)^2

The  ratio  of the perimeter  of the 10th triangle to the perimeter of the  3rd  triangle  is

(1/2)^9  / ( 1/2)^2   =    (1/2)^7  =   1 / 128    

50  -   [ 4.5 ( 1.28)  + 2.5(1.59)  + 6.4(.87)  ]  =

50  -   [   ≈ 15.03 ]    =

 ≈ $34.97  = change  received