What is the angle between two intersecting planes, such as the one between the horizontal ground and an aircraft plane during an aerial photo?

The angle between two intersecting planes, such as the one formed between the horizontal ground and an aircraft plane during an aerial photo, is referred to as the dihedral angle. This angle is a measure of the orientation of the two planes relative to each other and is important in various applications, including surveying, photography, and geometry.

In the context of aerial photography, understanding the dihedral angle helps in interpreting the images captured, as it affects the perspective and scale of the photograph. The dihedral angle is specifically defined as the angle formed by two intersecting planes, which makes it the most appropriate choice for describing the relationship between the horizontal ground and the aircraft's plane in this scenario.

Other options do not capture this specific relationship. For example, a horizontal angle pertains to measurements taken in a horizontal plane and is not applicable here. The optical axis relates to the line along which light travels through the camera lens, while a vertical angle measures angles relative to a vertical line. Thus, the characteristics of the dihedral angle are what make it the correct choice in this context.