Question

Find the surface area of the cylinder give your answer in terms of pi. The radius is 4mm and the height is 5mm

Answer 1

The surface area of a cylinder is the area of the bases plus the area of the side, or SA = 2*A₁ + A₂

Since the area of a circle is $\pi r^{2}$,
SA = 2*($\pi r^{2}$) + A₂

Since the area of the side is height * the circumference of the circle or A₂ = h * $2 \pi r$, then SA must be;

SA = $2* \pi (r ^{2} )+h*2 \pi r$
SA = $2* \pi (4 ^{2} )+5*2 \pi (4)$
SA = $32* \pi+80 \pi$
SA ≈ 351.858377202