This is an example of a t-shaped molecule. A t-shaped molecule has three shared pairs and two lone pairs. The bond angles are either 90 degrees or 180 degrees, but in the case of bromine trifluoride, the bond angle is 86.2 degrees. Bromine trifluoride has 28 valence electrons, and when you do the Lewis dot structure you are left with two lone pairs and three shared pairs around the central atom. Other examples of t-shaped molecules are ClF3 and IF3.