Answer:
[tex]A=50(1+\sqrt 2) \ cm^2[/tex]
Step-by-step explanation:
We have given that the side length of a regular octagon is 5 cm. It is required to find the area of this octagon.
The formula used to find the area of a regular octagon is :
[tex]A=2(1+\sqrt 2) a^2[/tex]
a is side length
So,
[tex]A=2(1+\sqrt 2) \times (5)^2\\\\A=2(1+\sqrt 2) \times 25\\\\A=50(1+\sqrt 2) \ cm^2[/tex]
So, the area of a regular octagon is [tex]50(1+\sqrt 2) \ cm^2[/tex].
