Answer:
B
Step-by-step explanation:
Whole circle is 360 degrees.
The railing is 120 degrees.
That is:
120/360 = 1/3 rd of the whole length of the circle (perimeter).
We will find perimeter of the circle (a.k.a. Circumference) and then multiply it by (1/3) to get meters of railing needed.
First, circumference:
[tex]C=2\pi r\\C=2 \pi (100)\\C=200\pi\\C=628.32[/tex]
The railing is (1/3)rd of it, so:
[tex]\frac{1}{3}*628.32=209.44[/tex]
The railing is 209.44 meters.
The answer choices are in pi, so it will be:
[tex]\frac{1}{3}*200\pi=\frac{200\pi}{3}[/tex] meters
Answer choice B is right
