A regular octagon has side length 10.9 in. The perimeter of the octagon is 87.2 in cm and the area is 392.4 in2. A second octagon has side lengths equal to 21.8 in. Find the area of the second octagon. Round to the nearest hundredth.
A. 261.60 in2
B. 1569.60 in2
C. 317.06 in2
D. 142.66 in2

Question

A regular octagon has side length 10.9 in. The perimeter of the octagon is 87.2 in cm and the area is 392.4 in2. A second octagon has side lengths equal to 21.8 in. Find the area of the second octagon. Round to the nearest hundredth.
	A.	261.60 in2
	B.	1569.60 in2
	C.	317.06 in2
	D.	142.66 in2

anonymous · Answer

do anybody know how to do this?

dumbcow · Answer

set up a proportion, the 2 areas are proportional to the ratio squared
$$\frac{x}{392.4} = \frac{21.8^{2}}{10.9^{2}}$$

anonymous · Answer

B.

anonymous · Answer

thanx