A certain coin is a circle with diameter 42 mm. What is the exact area of each side of the coin? The exact area of each side of the coin is mm.
(Simplify your answer. Type an exact answer in terms of .)

Figure abcd is a parallelogram. if point c lies on the line x = 2, what is the y-value of point c?

Jack has a piece of red ribbon that is two times as long as his piece of blue ribbon. he says that he can use two different equation to find out how long his piece of red ribbon is compared to his piece of blue ribbon is. is he correct? explain his reasoning

If you double the input of a function and it results in half the output, and if you triple the input and it results in a third of the output, what can be guessed about the function? check all that apply.