Is the distance around a circle . you calculate the of a circle by multiplying the diameter by 3.14

Ellen makes and sells bookmarks. she graphs the number of bookmarks sold compared to the total money earned. why is the rate of change for the function graphed to the left?

Which expressions equal 9 when x=4 and y=1/3 a. x2+6y b. 2x + 3y c. y2-21x d. 5 (x/2) -3y e. 3x-9y

The angle of elevation from point a to the top of the cliff is 38 degrees. if point a is 80 feet from the base of the cliff , how high is the cliff ?