Learn everything about cylinder with this free math topic guide, including step-by-step examples, free practice questions, and more! Learn about cylinders - their shape , volume, surface area, types, formulas, properties, and real-life examples. Solve problems easily with step-by-step solutions. A cylinder is a 3D geometric shape with two parallel circular bases connected by a curved surface . The height (h) is the distance between the two circular bases, while the radius (r) is the distance from the center to the outer boundary of each base.