An octagon is a polygon which has a total of 8 sides. An octagon is a closed geometric shape and area of an
octagon is the region covered inside by the bounded sides of the octagon. A regular octagon is the octagon
with all the side lengths equal to each other. Area of a regular octagon is the half times the product of its
perimeter and its apothem.
Example 1: Calculate the area of the octagon the side length is 8m.
Apothem of regular polygon is the line drawn from the center of the polygon to the midpoint of any of the
sides.
Apothem = (Side length)/ (2 * tan(180°/n))where n = number of sides
Apothem = 8m/ (2 * tan(22.5°) = 9.66m
Area of a regular polygon, A = 1/2 * Perimeter * apothem
For a regular octagon there are ‘8’ sides.
Hence Perimeter = n * side length= 8 * 8= 64m
Hence the area of the regular octagon, A = 1/2 * (64m) * (9.66m) = 309m2
Example 2: Calculate the area of the octagon the side length is 10m.
Apothem of regular polygon is the line drawn from the center of the polygon to the midpoint of any of the
sides.
Apothem = (Side length)/ (2 * tan(180°/n))where n = number of sides
Apothem = 10m/ (2 * tan(22.5°) = 12.07m
Area of a regular polygon, A = 1/2 * Perimeter * apothem
For a regular octagon there are ‘8’ sides.
Hence Perimeter = n * side length= 8 * 10= 80m
Hence the area of the regular octagon, A = 1/2 * (80m) * (12.07m) = 482.8m2