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
Step 2
To calculate the area of the hexagon multiply the area of one equilateral triangle by
cm²
therefore
the answer is the option
73.5 sqrt 3cm²
Total height of lumber, H = 10 1/2 feet = 21/2 feet .
Height of side panel, h = 5 2/3 feet = 17/3 feet .
Now,
Extra lumber required, L = 2 × Height of side panel - Total height of lumber
Therefore, extra lumber required is feet.
Hence, this is the required solution.