r = 15
The circumference of circle: [tex]C=2\pi r[/tex]
subtitute: [tex]C=2\pi\cdot15=30\pi[/tex]
[tex]1\ rad=\dfrac{180^o}{\pi}\to5\ rad=5\cdot\dfrac{180^o}{\pi}=\dfrac{900^o}{\pi}[/tex]
[tex]\dfrac{5\ rad}{360^o}=\dfrac{\frac{900^o}{\pi}}{360^o}=\dfrac{900^o}{\pi}\cdot\dfrac{1}{360^o}=\dfrac{5}{2\pi}[/tex]
[tex]s=\dfrac{5}{2\pi}C\to s=\dfrac{5}{2\pi}\cdot30\pi=75[/tex]
Answer: C. s = 75
