球面几何学 qiúmiànjǐhéxué spherical geometry Origin Definitions Defs Strokes Stroke Words Sentences Sents 球面 qiúmiàn sphere (mathematics) a curved surface formed by the rotation of a semicircle around its diameter几何学 幾何學 jǐhéxué geometry the branch of mathematics that studies the shape, size, and position of figures and the properties of space; also called 几何 jǐhé