Three charges are at the corners of an isosceles triangle where Q1 and Q2 are at the bottom of the triangle and Q3 is at the top (Q1 = 13 ?C, Q2 = 13 ?C and Q3 = 85 ?C). The length of the sides of the triangle are 3 m and the length of the bottom of the triangle is 4 m. Calculate the amount of work required to assemble this system of charges, assuming they are brought in from infinity.