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

sa = 2πr² + 2πrh
sa = 2π(6²) + 2π(6 x 2)
sa = 2π(36) + 2π(12)
sa = (2 x 36)π + (2 x 12)π
sa = 72π + 24π
sa = 96π

To solve this equation, isolate the variable for which you are solving (a) on one side of the equation and put everything else on the other side.

3a - 7z = 6a - 4z + 6
3a = 6a - 4z + 6 + 7z
3a - 6a = -4z + 6 + 7z
-3a = 3z + 6
a = \( \frac{3z + 6}{-3} \)
a = \( \frac{3z}{-3} \) + \( \frac{6}{-3} \)
a = -z - 2

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).

A cylinder is a solid figure with straight parallel sides and a circular or oval cross section with a radius (r) and a height (h). The volume of a cylinder is π r²h and the surface area is 2(π r²) + 2π rh.

Perimeter is equal to the sum of the four sides:

p = a + b + c + d
p = 7 + 2 + 5 + 8
p = 22