Answer:
A = 3.4 cm
Step-by-step explanation:
The length of line segment AB is 3.4cm.
The area of octagon is given as 2a^2(1+sqrt{2})
Where a is the side of octagaon. All sides of octagon are same.
As, 2a^2(1+sqrt{2}) = 54cm
Then, a^2 = 54/2(1+sqrt{2})
a^2 = 54/4.828
a^2 = 11.19
a = 3.4 cm
