First, remember the formula for the circumference of a circle is C= 2πr. Then remember that the diameter is twice the radius.
So here, when we have a diameter of 10ft, and we see the formula for circumference is C= 2πr, and because a Diameter is equal to 2 radii, I can also say C= Dπ. So in your case C= 10ft×π = 10ftπ
3 parts water clean:water=1:3 1:3=xcleaner:1gallon 1/3=xcleaner/1gallon times 3gallon both sides 1gallon=3xcleaner divide both sides by 3 1/3 gallon=xcleaner
