Question

A regular octagon with sides of length 11 and an apothem of length 8.85 has an area of _____ square units.

Answer 1

Answer: 389.4

Step-by-step explanation: I tested it and it was correct :)

Answer 2

Given the apothem (a) and the side of the regular polygon, the area (A) of the polygon may be calculated by the formula, 
     
                                 A = aP/2

where P is the perimeter. 

Given that the octagon has a length of 11, its perimeter is 88. Substituting this to the formula above, 
 
                                A = (8.85)(88) / 2 = 389.4

Thus, the area of the polygon is 389.4 unit².