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.

According to the Pythagorean theorem, the hypotenuse squared is equal to the sum of the two perpendicular sides squared:

c² = a² + b²
c² = 3² + 7²
c² = 9 + 49
c² = 58
c = \( \sqrt{58} \)

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

z² - 49 = 0
(z - 7)(z + 7) = 0

For this expression to be true, the left side of the expression must equal zero. Therefore, either (z - 7) or (z + 7) must equal zero:

If (z - 7) = 0, z must equal 7
If (z + 7) = 0, z must equal -7

So the solution is that z = 7 or -7

A triangle is a three-sided polygon. It has three interior angles that add up to 180° (a + b + c = 180°). An exterior angle of a triangle is equal to the sum of the two interior angles that are opposite (d = b + c). The perimeter of a triangle is equal to the sum of the lengths of its three sides, the height of a triangle is equal to the length from the base to the opposite vertex (angle) and the area equals one-half triangle base x height: a = ½ base x height.

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).