What is the area of a regular hexagon with apothem 7.5 inches? What is its perimeter?

1 Answer

A hexagon can be split up into 6 equilateral triangles.
If one of these triangles has a height of 7.5 in, then (using the properties of 30-60-90 triangles, one side of the triangle is #(2*7.5) / sqrt3= 15/sqrt3 = (15sqrt3)/3#.
Since the area of a triangle is #(1/2)*b*h#, then the triangle's area is #(1/2)(15sqrt3/3)*(7.5)#, or #(112.5sqrt3)/6#. There are 6 of these triangles that make up the hexagon, so the area of the hexagon is# 112.5*sqrt3#.

For the perimeter, again, you found one side of the triangle to be #(15sqrt3)/3#.
This is also the side of the hexagon, so multiply this number by 6.