Find the surface area of a sphere whose radius is 3.5cm, correct your answer to one decimal place (\pi = \(\frac{22}{7}\))
A
12.8cm2
B
25.7cm2
C
77.0cm2
D
154.0cm2
E
179.7cm2
Verified Correct Answer: D.
Step-by-Step Mathematical Solution
Surface area of a sphere
\(A = 4\pi r^2 \)
\(r = 3.5 = \frac{7}{2},\quad \pi = \frac{22}{7}\)
\(A = 4 \times \frac{22}{7} \times \left(\frac{7}{2}\right)^2 = 4 \times \frac{22}{7} \times \frac{49}{4}\) = 154
Source: Myschool Past Questions Archive (Record #42247)