The surface area of a cylinder is S=2pir2+2pirhS = 2\\pi r^2 + 2\\pi rhS=2pir2+2pirh. Factor the right side.
2pir(r+h)2\\pi r(r + h)2pir(r+h)
2pi(r2+h)2\\pi(r^2 + h)2pi(r2+h)
2pir2(1+h)2\\pi r^2(1 + h)2pir2(1+h)
2pir+2pirh2\\pi r + 2\\pi rh2pir+2pirh