Can somebody pls help

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

For problems 29 - 31 the graph of a quadratic function y=ax^2 + bx + c is shown. tell whether the discriminant of ax^2 + bx + c = 0 is positive, negative, or zero.

Mia’s gross pay is 2953 her deductions total 724.15 what percent if her gross pay is take-home pay