The answer is three significant figures. The 1 and the 7 are both significant, because they are non-zero quantities.
This is where significant figures gets a little more complicated, because if a zero is used as a placeholder (i.e. 0.00027 cm) then it is insignificant.
But in the case above, the zero isn't being used as a placeholder, and thus, is significant.
Hi,
Let assume a the west side,
b the length of the north wall (i suppose the answer is smaller then the barn.
Cost of the fence= a*6+a*12+b*12=3000 $.
So 3a+2b=500==>b=(500-3a)/2
Area =a*b=a(500-3a)/2= 250a-3/2a²
Derivate the area ==> 250-3a=0
==> a=250/3 and b=(500-3*250/3)/2=125
Width=125 (feet)
Length=250/3=83.333 (feet)
Circumference = 2 * pi * r, where r is the radius
For this circle, the circumference is 11pi, so 11pi=2*pi*radius. Divide both sides by 2pi and you get r is = to 5.5 inches.
Area of a circle is pi*r^2. Since we just saw that r = 5.5 inches, the circle has an area of 5.5 inches * 5.5 inches * pi or 30.25 pi inches squared.
A because 12*4=48 and 32*4=128
