What is the circumference of a circle with a diameter of 30

How do i do this? i don’t understand

Graph g(x)=2cosx . use 3.14 for π . use the sine tool to graph the function. graph the function by plotting two points. the first point must be on the midline and closest to the origin. the second point must be a maximum or minimum value on the graph closest to the first point.

Write a fraction less than 1, which has a denominator of 6 and is greater than 3/4 plz answer !