trigonometry

n [U] branch of mathematics dealing with the relationship between the sides and angles of triangles, etc 三角学.

trickiness, trickle, trickle charger, trickster, tricky, tricolour (US tricolor), tricycle, trident, tried, triennial, triennially, trier, trifle, trifler, trifling, trigger, trigger-happy, triglyceride, trigonometric, trigonometrical, trigonometrically, trike, trilateral, trilaterally, trilby, trilingual, trill, trillion, trillionth, trilobite, trilogy, trim, trimaran, trimmer, trimming, trinitrotoluene, trinity, Trinity Sunday, trinket, trio, trip,