#1 Pi was originally as the ratio of a circle's circumference to it's diameter.
#3 Pi cannot be completely represented as a fraction, but 355/113 is pretty close.
#6 A irrational number is a number that can't be represented as a ratio/fraction
#8 Is because March is the third month, and 14 is the first to decimals. Month/Day: 3/14, Pi: 3.14.
Sorry, that's all I know.