Answer:
Setting
Step-by-step explanation:
Answer:
Rate of change of y is 
Step-by-step explanation:

(1) the diameter is 20 inches whats the radius? And whats the circumference?
Radius is half the diameter, Answer: 10 inches
Circumference is pi times the radius, Answer: 10π inches
I won't bother with the approximation, though this one is easy, 31.4159 inches. I'll leave the rest of the calculator work to you if necessary.
(2) the diameter 11 inches whats the radius? And whats the circumference?
Radius half, Answer: 5.5 inches. Circ: 5.5π inches
(3) the diameter 3.5 inches whats the radius? And whats the circumference?
Radius, 1.75 inches. Circ: 1.75π inches
With a square or rectangular shape, the formula for figuring out how big an area is is simple: multiply the length and width of the shape by the square feet is the surface area of a pool that is feet long and feet wide (8x 10).