1.C 三角形；三角形物体 geometric figure with three straight sides and three angles; thing shaped like this 2.C 三人一组；三角关系 situation involving three people, ideas, opinions, etc.
句型例句
He drew a right triangle.他画了一个直角三角形。 The place is a cobbled triangle.这个地方是一块铺石子的三角地。 Finance, fashion and flourish—the triangle upon which the store was built.资金充裕、款式新颖和装潢华美曾是那家商店的三大支柱。