<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.
A vertex can be the max or min. The vertex is the highest point or lowest point of a function.
For straight lines the constant rate of change(slope) is a constant(always the same) For every unit moved on the x-axis two more are moved on the y-axis