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(1) We know that a regular hexagon can be seen to be made up of 6 equilateral triangles, as shown in the figure above.
It is clear from the image that \(BE = \) Twice the length of a side of the equilateral triangle. Hence, \(EF = 7\) and \(CF = 14\).
Now that we have the hypotenuse and the base, we can apply
Pythagoras' Theorem to find the height too.
(Notice that the triangle \(FCE\) is right-angled and this can be proved.)\(CE^2 + EF^2 = CF^2\)
\(\Rightarrow CE^2 + 49 = 196\)
\(\Rightarrow CE^2 = 147\)
\(\Rightarrow CE = 7 \sqrt{3}\)
Hence,
Area of Triangle \(FCE \)= \(\frac{1}{2}(EF)(CE)\)
\(= \frac{1}{2}(7)(7 \sqrt{3})\)
\(= \frac{49}{2}\sqrt{3}\)
=>
Sufficient(2) Just given \(EC = 7 \sqrt{3}\) does not tell us anything about the nature of the hexagon and we cannot deduce the other sides of the triangle, and hence cannot find the area.
=>
InsufficientAns:
Option A