Question

Circles problems >.<

Answer 1

I really dont know how to do this.

Answer 2

Well kind of im not sure how to get the outer rim area

Answer 3

The given image represents a Ring.
Area of ring is :

\[\pi(R^2 - r^2)\]

Where,
R = 18 yards
r = 14 yards

Answer 4

18 times 18 = 324
14 times 14 = 196

324 - 196 = 128

Area of Annulus (Ring):
pi*(R^2 - r^2)
pi*(18^2 - 14^2)
pi*(324-196)
pi*128

3.14*128 = 401.92 sq yards

Answer 5

Now use unitary methods

Given one bag of sand can cover 4 sq yard.
So x number of bags can cover 401.92 sq yards.

Frame an equation for the above data:

Bags Area
1 4
x 401.92

Cross multiply:

4*X = 401.92*1
4x = 401.92
x = 401.92/4
x = 100.48

Approximate value of x is 100.5(rounding off 100.48)

But since the question asks us to keep it in whole number the ans must be 100 bags.

Answer 6

Thank you very much for the formula! This was very helpful