Which approximation is closer to the actual of pi-3.14 or 22/7, and explain?

You see that the two numbers 3.1416 and 22/7 are both close to Pi and to each other in value. The actual circumference of a 10 foot diameter circle is 10*Pi feet, or about 31.4159265 feet, or 31 feet 4.991118 inches. If you use 10*3.1416 = 31.416 feet, you get 31 feet 4.992 inches. These answers differ by only 0.000882 inches - - very close! If you use instead 10*22/7 = 31.4285714 feet, you get 31 feet 5.142857 inches. These answers differ by 0.1517387 inches, or about 5/32 inches. That isn't bad, either. The result of this analysis is that for most purposes, 22/7 is a pretty good estimate of Pi (three significant figures), and 3.1416 is better (five significant figures), but if you need very high accuracy, you should use an even more accurate estimate of Pi. Decide what accuracy you need, and round the value of Pi to that many significant figures. Then use that times the diameter to get the circumference.