Question

(Answer with steps please)

Answer 1

Answer:

Step-by-step explanation:

a). Total surface area of cylinder is defined by sum of curved surface area and surface area of the top and bottom.

Total surface area = 2πrh + 2πr²

Skateboarders use a half pipe structure which are not closed at the ends.

Therefore, curved surface of the half pipe = $\frac{2\pi rh}{2}$

                                                                      = πrh

b). If r = 2.5 m and h = 9 m,

Curved surface area of the half pipe = π(2.5)(9)

                                                             = 70.69 m²

                                                              ≈ 71 m²