The circumference of a hula hoop is 86 pi cm. What is the radius of the hula hoop?

What percent of the circle below is shaded?

What is the frequency of the sinusoidal graph?

Boris needs to buy plastic spoons. brand a has a box 42 spoons for $2.37. brand b has a box of 72 spoons for $3.57. find the unit price for each brand. then state which brand is the better buy based on the unit price. round your answer to the nearest cent.