Final answer:
The ball-and-stick model is the one that would show the bond angle in a molecule, as it represents the three-dimensional arrangement of atoms and the bonds between them.
Step-by-step explanation:
The model that would show the bond angle is the ball-and-stick model. This model represents molecules three-dimensionally, using "balls" for atoms and "sticks" to represent the bonds connecting them. The bond angle is the angle between any two bonds that include a common atom, and the ball-and-stick model allows you to visualize these angles clearly.
In contrast, a space-filling model emphasizes the relative sizes of atoms without clearly delineating bond angles, and structural formulas indicate connectivity but often do not depict the three-dimensional structure and thus the bond angles accurately. The condensed structural formula and the formula provide the least three-dimensional structural information and do not show bond angles at all.