The cylinder, with its simple yet elegant design, is a testament to the beauty of three-dimensional geometry. Whether it’s holding your morning coffee, powering your car’s engine, or shaping the skyline of a city, the cylinder plays a vital role in life. Understanding its properties and applications enriches comprehension of the world of 3D shapes and highlights the practical significance of this marvellous geometric figure.

**Applications of Cylinders**

**Engineering and Construction:**Cylindrical shapes are prevalent in engineering and construction, from pipes and columns to storage tanks and hydraulic cylinders.**Transportation:**Cylinders are essential components in engines, where they convert linear motion into rotary motion, thus powering vehicles and machines.**Containers:**Many everyday items, such as cans, bottles, and jars, have cylindrical shapes for easy storage and transportation.**Mathematics and Geometry:**Cylinders serve as fundamental examples in geometry, and are very helpful in understanding concepts like volume and surface area.**Science:**In scientific experiments, cylindrical containers are used to hold liquids and gases, making them invaluable in laboratory settings.

Cylinders come in various forms, depending on the shape of their bases. The two most common types are:

**Right Cylinder:**In a right cylinder, the axis (an imaginary straight line connecting the centers of the two circular bases) is perpendicular to the bases, resulting in straight sides. This is the most common type of cylinder.**Oblique Cylinder:**In an oblique cylinder, the axis is not perpendicular to the bases, causing the sides to slant. These cylinders are less common and are often used for specialized applications.

So, cylinder is a three-dimensional geometric shape that has two congruent, parallel circular bases and a curved surface that connects these bases.

The two bases are perfectly aligned, and the distance between them is known as the height (h) of the cylinder. The radius (r) of the circular bases is the distance from the center of each base to its outer edge.

**Formulas and Properties:**

**Volume (V):**The volume of a cylinder can be calculated using the formula V = πr²h, where π (pi) is approximately 3.14159, ‘r’ is the radius of the base, and ‘h’ is the height of the cylinder. This formula tells how much space the cylinder occupies.**Surface Area (A):**The total surface area of a cylinder consists of the areas of its two circular bases and the curved surface. The formula for the surface area is A = 2πr² + 2πrh.**Lateral Surface Area (LSA):**To find just the curved surface area without the two circular bases, use the formula LSA = 2πrh.**Diameter (d):**The diameter of a cylinder is twice the radius, i.e., d = 2r.**Circumference (C):**The circumference of each circular base can be calculated using the formula C = 2πr.