What does equilateral triangle mean

What is the approximate circumference of the circle shown below?

Complete the solution of the equation. find the value of y when x equals to 28 x+3y=28

Someone answer asap for ! the following statements are true about the coins calvin and sasha have collected. * calvin and sasha has the same amount of money. * calvin has only quarters. * sasha has dimes, nickels, and pennies * calvin has the same number of quarters as sasha has dimes. * sasha has $1.95 in coins that are not dimes. exactly how many quarters does calvin have?