Question 1104721
It's an equilateral triangle with sides = a
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base b = a
Height h = sqrt(a^2 - (a/2)^2) = a*sqrt(3)/2
{{{Area = b*h/2 = a^2*sqrt(3)/4}}}
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For any regular polygon with n sides = s:
Area = ns^2*cot(180/n)/4
= 3a^2*cot(60)/4
= a^2*sqrt(3)/4 ---- same answer