ElectricPavlov

Diameter = 27     Radius (r) = 13.5

Circumference = pi x Diameter = pi x 27

Area = pi r^2 = pi (13.5)^2

I think you can take it from here ! 

= 92/9 + 121/8

= (736+1089)/72 = 1825/72 = 25 25/72

or

= 10 + 15    +  2/9 + 1/8

=25 + (16 +9)/72 = 25 25/72

= 4(sqrt3)/2 x 48(1/2)

4sqrt3 /2 x 24

48 sqrt3

Five

c1   pi x d = 9     so d= 9/pi   radius = 9/(2pi)     Area = pi r^2   pi (9/(2pi))^2 =  pi (81/(4pi^2) =81/(4pi)

c2                            d=2pi/pi =2   radius =1     Area = pi r^2   = pi

ratio area c1/c2 =     81/(4pi)  /  pi =   81 / (4pi^2)

Are you sure the first circle c1 circumference was not 9pi ??   If it was, the ratio works out to 20.25     (the same as 9^2 / 2^2)

The circle has more area:

pi x d = circumference

pi x d = 50     d= 15.91  so r= 1/2 d = 7.96cm    Area = pi r^2 = pi (7.96)^2 = 198.9 sq cm  (Circle)

The square has four sides   4x=50   x=side length= 50/4 = 12.5cm    Area = 12.5 x 12.5 = 165.25 sq cm (Square)

Maybe you should stay in summer school for English?   It's "Bye-bye"     not   "by by"  .

FV = PV (1+i) ^n        i = interest in decimal for the periods    n = periods   

     =2400(1.02)^7 = $ 2756.85

Sorry.....going to need a LITTLE more information about this.....

Thanx!   Geno.....