In what context is "high angle fire" utilized with mortars?

High angle fire is particularly effective for targeting objects behind cover because it allows the projectile to ascend to a steep angle and then descend directly onto the target from above. Mortars, which are designed to fire at steep angles, can lob shells over obstacles such as hills, buildings, or other forms of cover that would block a direct line of sight. This capability makes high angle fire a strategic choice in combat situations where enemies are sheltered by terrain or fortifications, enabling forces to engage targets that would otherwise be difficult to hit using traditional direct fire methods.

The other contexts mentioned are not suitable for high angle fire. Utilizing mortars for direct fire against advancing tanks is impractical, as mortars are not designed for such engagements. Increasing range for distant targets may involve adjustments in fire techniques, but it doesn't specifically relate to high angle fire, which focuses more on overcoming terrain obstacles. Firing at low altitude contradicts the concept of high angle fire, which inherently involves steep trajectories. Thus, the context of targeting objects behind cover aligns perfectly with the function of high angle fire in mortar operations.