Step 1
Find the area of one equilateral triangle
Applying the law of sines

in this problem
a=b=7 cm
C=60 degrees
so

 cm²
cm²
Step 2
To calculate the area of the hexagon multiply the area of one equilateral triangle by 

![Area Hexagon=6*[49*(√(3))/(4)] \\ Area Hexagon=73.5*√(3)](https://img.qammunity.org/2017/formulas/mathematics/high-school/yaub92x4ym3ht1woxxt1f99i53xeazxi83.png) cm²
cm²
therefore
the answer is the option 
73.5 sqrt 3cm²