I think what you are wanting id 0.1 is that rounded to one significant figure
<u>Given</u>:
Given that the regular decagon has sides that are 8 cm long.
We need to determine the area of the regular decagon.
<u>Area of the regular decagon:</u>
The area of the regular decagon can be determined using the formula,

where s is the length of the side and n is the number of sides.
Substituting s = 8 and n = 10, we get;

Simplifying, we get;




Rounding off to the nearest whole number, we get;

Thus, the area of the regular decagon is 642 cm²
Hence, Option B is the correct answer.
If it is rational, it has a terminating decimal or a repeated decimal number (ex. 56, or 1.25, or 3.666...)
If it is irrational, it is an ongoing number with no pattern (ex. 3.14159265... Which is pi)
115 is n that’s the answer