Question

Find the area of a circle circumscribing equilateral triangle of side $15cm$.[Take $\pi =3.14$]

• A. $235.5$ $c{m}^2$
• B. $236.5$$c{m}^2$
• C. $237.5$ $c{m}^2$
• D. $238.5$ $c{m}^2$

Answer 1

The correct option is A $235.5$ $c{m}^2$

Let the radius of the circle be $r$ , this circle also circumscribing the equilateral triangle of side $a$ = 15 cm

so from the relation between radius and side of triangle we get( hint: find by drawing the diagram :) )
$r=\frac{15}{\sqrt{3}}$ cm
Area of the circle $=\pi (\frac{15}{\sqrt{3}}{)}^2$
$=3.14\times \frac{225}{3}$
$=235.5c{m}^2$