How would you find the area of a 12 sided polygon with a side "s" and apothem "a"?

Cut the 12 sided polygon into 12 triangles all connected together at the center. These triangles have base "s" and height "a", so 1/2 base * height = area of 1 triangle = 1/2 s * a. You have 12 of them all together, so 6 * (1/2 * s * a) so 6 * s * a