A simple way to calculate the distance between numbers on a number line is to count every number between them. A faster way is to find the distance by taking the absolute value of the difference of those numbers. We have to find PQ. TAking the difference we have 94-91= 3.
500=4πr^2. first divide 500 from four which will equal 125, then divide 125 with π and it will equal 39.788 . finally √39.788. the answer will be r=6.3 or 6