Answer:
578 cm^2
Step-by-step explanation:
The surface area is given by one circle of radius 4 (the other is missing!), plus a "rectangle" (the lateral surface) of sides 21 and [tex]2\pi \times 4[/tex] (the length of the circumference at the base). Adding them up we get:[tex]\pi \times4^2 + 21\times 2\pi\times4 = 184\pi \approx 578 cm^2[/tex]
