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# triangles

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A circle is circumscribed about an equilateral triangle with side lengths of 9 units each. What is the area of the circle, in square units? Express your answer in terms of pi.

bbelt711  Jul 26, 2017
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Equilateral triangle radius of circumcircle = $$\frac{s}{\sqrt{3}}$$

Which means $$r = 3\sqrt{3}$$

Area of a circle is Pi*r^2

Substitute to get $$\Pi ({3\sqrt{3})}^2$$

Which is equal to $$27\Pi$$

The area of the circumcircle is $$27\Pi -units^2$$

Mathhemathh  Jul 26, 2017