Question

smaller-than-usual tidal ranges, called ____ tides, occur when the sun and the moon are at a 90-degree _____ to each other relative to the earth. during first and third quarter phases the gravitational forces are not aligned, and high tide from the moon overlaps low tide from the sun. this results in a slightly lower high tide, and a slightly higher low tide.

Explanation:

Smaller tidal ranges occur when the Sun and Moon form a right angle relative to Earth, during first/third moon quarters. These tides are named neap tides, and the geometric relationship is a 90-degree angle (or "angle" / "orientation" where they are perpendicular).

Answer:

1. neap
2. angle (or perpendicular)