9514 1404 393
Answer:
200√2 square units
Explanation:
The area of a regular polygon with n sides and radius r is given by the formula ...
A = (n/2)r²·sin(360°/n)
Here, we have n=8 and r=10, so the area is ...
A = (8/2)(10²)sin(360°/8) = 4·100·√2/2
A = 200√2 . . . square units