Dr.Strange (movie title) whats ur real name???(srry for pers. quest.)Find the centre of mass of an equilateral triangle whose all sides are L.

@ vaibhav 
u need to directly apply the formula over here , 

like L= AB COS 30 DEGREE 
and the ques seems incomplete as u have not mentioned the mass of three particle present in the equilateral triangle , 
and also L needs to be of some value 
lets take L = 0.5 m 
so, L = AB COS 30 
= 0.5 * ROOT3/2 
= 0.43 M 
here we need the masses of three particle to proceed further 
use the formula 
X = ma x1 + mbx2 + mcx3 / ma+mb+mc 
then proceed on 
ALL THE BEST ..