"Formula of a circle" is too vague to be meaningful. Perhaps you meant, "Formula for the area of a circle in terms of its circumference."
The area of a circle in terms of its radius is A = πr^2. To put this formula to use, we have to know the radius of the circle. The circumference of a circle in terms of its radius is C = 2πr, so a formula for the radius is r = C / (2π).
Now let's find a formula for the area of a circle in terms of its circumference:
C C^2
A = πr^2 = π { ---------------- }^2 = ------------
2π 4π
or:
A = (C^2) / 4π
Answer:

Step-by-step explanation:
The length of the trail is obtained by the definition of sine, where height is the opposite leg and length is the hypotenuse:

The length of the trail is:

Answer:
I think it's b or d
Step-by-step explanation:
Answer:
The width is independent, w, and the length is dependent, 2w - 5. If discussing the area then the independent is w and the dependent is Area for A = (2w-5)(w).
Step-by-step explanation:
On a graph called the coordinate plane, there are two axis. The horizontal axis is the x-axis and is known as the independent variable. A great example of an independent variable is time. Time is always represented on the x-axis because time passes by. It does not depend on anything.
The other axis is the y-axis. It is the vertical axis on the graph. It is called the dependent variable because its value depends on x. For example, if you were looking at miles per hour, the number of miles would depend on how many hours you traveled. You have to know the time to find miles. This is a dependent variable.
Here w can be anything and it affects what the length 2w - 5 will be. It determines it because it is part of the expression. The independent variable is w and the dependent variable is the length 2w - 5. If discussing the area then the independent is w and the dependent is Area for A = (2w-5)(w).