In Bow’s notation, used in structural analysis (especially for trusses), each triangle’s sides are labeled with capital letters placed in the spaces between the forces. To find the forces in the sides (members) of a triangle, you refer to the letters on either side of a force line. These labels help identify internal forces by showing which areas the force separates. So, to find the sides, you look at the pair of letters (like A-B or B-C) that border each member.