Q: Is diameter also called the diameter? ¶
A: Yes.
Q: Is diameter an important global Riemannian invariant? ¶
A: Yes.
Q: Is diameter the same because all such pairs of parallel tangent lines have the same distance? ¶
A: Yes.
Q: Is diameter called the major axis? ¶
A: Yes.
Q: Is diameter defined to be the largest distance that can be formed between two opposite parallel lines tangent to its boundary? ¶
A: Yes, and the width is often defined to be the smallest such distance.