The surface area of a penny can be calculated by considering both its flat circular faces and the cylindrical edge. A typical U.S. penny has a diameter of 19.05 mm and a thickness of 1.52 mm. The surface area includes the area of the two circular faces and the edge (circumference times thickness).
Using the formula for the area of a circle (A=Ï€r2) and the circumference (C=2Ï€r), the total surface area is approximately:
2(πr2)+(2πr⋅h)=2(π⋅9.5252)+(2π⋅9.525⋅1.52)≈721.25mm2
So, the total surface area of a penny is roughly 721 mm².