The formula for circumference is circle diameter x π. Circle diameter is 2 x radius:

c = πd
c = π(2 * r)
c = π(2 * 16)
c = 32π

A circle is a figure in which each point around its perimeter is an equal distance from the center. The radius of a circle is the distance between the center and any point along its perimeter. A chord is a line segment that connects any two points along its perimeter. The diameter of a circle is the length of a chord that passes through the center of the circle and equals twice the circle's radius (2r).

The formula for area is πr². Radius is circle \( \frac{diameter}{2} \):

r = \( \frac{d}{2} \)
r = \( \frac{10}{2} \)
r = 5
a = πr²
a = π(5²)
a = 25π

To multiply monomials, multiply the coefficients (the numbers that come before the variables) of each term, add the exponents of like variables, and multiply the different variables together.

(3a)(7ab) - (9a²)(5b)
(3 x 7)(a x a x b) - (9 x 5)(a² x b)
(21)(a¹⁺¹ x b) - (45)(a²b)
21a²b - 45a²b
-24a²b

The surface area of a cylinder is 2πr² + 2πrh:

sa = 2πr² + 2πrh
sa = 2π(8²) + 2π(8 x 6)
sa = 2π(64) + 2π(48)
sa = (2 x 64)π + (2 x 48)π
sa = 128π + 96π
sa = 224π