A = 6 * (1/2 * apothem * side) ... 6 triangles with a height of 'a' (apothem) and base of 's' (side).
A = 6 * (1/2 * a * s) ,
42 = 6 * (1/2 * a * 7) ,
a = 2 cm ... that's the way you can find your given answer BUT IT IS WRONG AS ...
The area of a regular hexagon with a side of 7 is 7^2 * (2√3)2 = 127.31 cm^2.
Area = (side)^2 * 2(√3)/2
