Hi everyone again, I need help on this, help me out please.

True or false? many triangular shapes can be circumscribed about a given circle

Acircle has a circumference of 28.36 units what is the diameter of the circle

The distribution of the amount of money spent by students for textbooks in a semester is approximately normal in shape with a mean of $235 and a standard deviation of $20. according to the standard deviation rule, how much did almost all (99.7%) of the students spend on textbooks in a semester?