Question

The area of a regular octagon is 35 cm². What is the area of a regular octagon with sides three times as long? (1 point)315 cm²
175 cm²
225 cm²
105 cm²

Answer 1

I just multiply the original area by 3 right??

Answer 2

hmmm, im not sure if that is quite correct. personally i would find the sides of the octagon from the area equation and then redo the problem.

Area of a octagon = side^2(2+2(sqrt(2)))
35cm^2=side^2(2+2(sqrt(2))
35/(2+2(sqrt2)=side^2
7.25=side^2
sqrt(7.25)=side=2.69

Answer 3

i would then multiply each side by 3 and plug that into the equation:

2.69*3=8.07
area=side^2(2+(2sqrt(2))
area=8.07^2(2+(2sqrt(2)
area=315cm^2

Answer 4

Why multiply by 3?

Answer 5

because each side is 3 times as long

Answer 6

ohhhh

Answer 7

so that is why cant multiply the total area by 3, because it says that each side is 3times as long, not the total area is 3times as big

Answer 8

Oh ok...THANK YOU!!

Answer 9

no problem