Answer:
The answer is
[tex]18\sqrt{3} [/tex]
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Step-by-step explanation:
This triangle is equilateral
Then
[tex]db = \frac{1}{2} ab = .5 \times 12 = 6 [/tex]
By using the phythgorth thearm you can find CD
[tex]cd = \sqrt{ {ab}^{2} - {db}^{2} } \\ = \sqrt{144 - 36} = 6 \sqrt{3} [/tex]
Then the eara of triangle is
[tex] \frac{1}{2} \times 6 \times 6 \sqrt{3} = 18 \sqrt{3} [/tex]