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.

The surface area of a cube is (2 x length x width) + (2 x width x height) + (2 x length x height):

sa = 2lw + 2wh + 2lh
sa = (2 x 1 x 5) + (2 x 5 x 8) + (2 x 1 x 8)
sa = (10) + (80) + (16)
sa = 106

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).

An isosceles triangle has two sides of equal length. An equilateral triangle has three sides of equal length. In a right triangle, two sides meet at a right angle.

The first step to solve a quadratic equation that's set to zero is to factor the quadratic equation:

z² - 7z + 6 = 0
(z - 1)(z - 6) = 0

For this expression to be true, the left side of the expression must equal zero. Therefore, either (z - 1) or (z - 6) must equal zero:

If (z - 1) = 0, z must equal 1
If (z - 6) = 0, z must equal 6

So the solution is that z = 1 or 6