A hypocycloid in which the radius of the rolling circle is a quarter of the radius of the fixed circle. It has parametric equations x = a cos3t, y = a sin3t, where a is the radius of the fixed circle.
An astroid
- bastnäsite
- Basu, Debabrata (1924–2001)
- Basu theorems
- BAT
- bat
- Bataille, Georges (1897–1962)
- Batavia
- Batavian Republic
- batch
- batch control
- batch culture
- batch distillation
- Batcher’s parallel method
- batch learning
- batch process
- batch processing
- batch production
- batch reactor
- Batesfordian
- Bates, Henry Walter
- Batesian mimicry
- Bateson, William
- bathochromic shift
- batholith
- Bathonian