This image shows the "base" or fundamental roots for B3 (red balls) and the fundamental weights (blue

balls). Each fundamental weight is perpendicular to two of the fundamental roots and projects orthogonally

to one-half of the third fundamental root. The fundamenatal root having a blue line is perpendicular to

the fundamental root toward the back of the image. The two fundamental roots in the horizontal plane

are at an angle of 135 degrees and have a length ratio of sqrt(2). The two green fundamental roots are

at an angle of 120 degrees and have equal length. This leads to the Dynkin diagram for B3: one single

bond (equal length, 120-degree angle) and one double bond (sqrt(2) length-ratio, 135-degree angle).