A regular decagon has sides that are 8 cm long. What is the area of the figure? Round to the nearest whole number.

Given:

Given that the regular decagon has sides that are 8 cm long.

We need to determine the area of the regular decagon.

Area of the regular decagon:

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.