what shape?; what type?; which model?
General question word for asking about the shape, type, or model of something. Often used in contexts like blood type, personality types, or product models.
What model is this part?
What personality type do you think he has?
which blood group?
Specifically used when asking about blood type, often in the context of blood-type personality theories or medical situations. The cross-reference to 血液型 (けつえきがた) indicates this specialized usage.
See also: 血液型 (けつえきがた)
What's your blood type? I'm type A.
Compound of 何 (なに, 'what') and 型 (がた, 'type, shape, model'). The reading がた is a rendaku form of かた when used as a suffix.