"Three equal point charges, each with charge 1.45 x 10^-6 C , are placed at the vertices of an equilateral triangle whose sides are of length 0.650 m...

"Three equal point charges, each with charge 1.45 x 10^-6 C , are placed at the vertices of an equilateral triangle whose sides are of length 0.650 m . What is the electric potential energy of the system? (Take as zero the potential energy of the three charges when they are infinitely far apart.)"