locate centere of mass three particles 1kg ,2kg and 3kg

respectovely at the corneres of an equliteral triangle of 1m on sides

AAAaannndd the bot gets it wrong yet again!

only if the masses are all equal.
Here you have to take the weighted average.

The center of mass of the three particles is located at the intersection of the medians of the triangle, which is also the center of the triangle. This point is located at (0.5 m, 0.866 m).