Question 172841
You need the equations for circumference and area of a circle.
C = 2 * pi * r
and
A = pi * r^2


Changing the first equation so that you can solve for the radius if you know the circumference gives you:

C / (2 * pi) = r

If the circumference of the circle is 2500 cm, the radius = 2500/(2*pi). Substituting 3.1415 in for pi will give you the number.


Now that you have the radius, you can calculate the area as pi * r^2.




The 3 pieces of wire have to total a length of 30 ft. If the shortest length is x, then we could write the length of the longest piece as 4x and the length of the middle-sized piece as 3x-___ . Fill in the blank with the number from the problem. (It is missing in your question. Since the length of the 3 pieces equals 30, the equation to solve is:
x + 4x + 3x-___  = 30
Once you solve for x, you can calculate the lenghts of the 3 pieces.