To calculate the surface area of a cylinder: Work out the area of the two circular faces (2 × π\(r\)²). Work out the curved surface area, this is the rectangular face (2π\(r\) × \(h\)).

This reduces the area of a non-stretchable but flexible ... They described their findings in “Developing the Nondevelopable: Creating Curved-Surface Electronics from Nonstretchable Devices ...