Join the center of the hexagon with the 2 base angles.
An equilateral triangle, with side length x, is formed.
(remark: a regular hexagon is made up of 6 equilateral triangles with equal length)
The height

forms 2 congruent right triangles with :
hypotenuse= x, side_1=x/2, and side_2=

.
From the pythagorean theorem we have:




thus, x=4.
The area of the triangle is 1/2 * 4 *

=6.93 (mm squared)
The area of the hexagon is 6* the area of the triangle = 42 (mm squared)
Answer: a. 42 (mm squared)