Question

an equilateral triangle is inscribed in a circle of radius10cms.find the length of sides an hence its area

Answer 1

Side of an equilateral , let it be a
.Now, Side of a an equilateral circumscribed by a circle =
$r \sqrt{3}$

$10 \sqrt{3}$
Required area of the triangle =
$\sqrt{3 } a { }^{2} \div 4$
=
$300 \sqrt{3} \div 4 = 75 \sqrt{3}$