subtend

v [Tn] (geometry 几) (of a chord2(1) or the side of a triangle) be opposite to (an arc(1) or angle) （指弦或三角形之边）对向（某弧或角）: The chord AC subtends the arc ABC. The side XZ subtends the angle XYZ. AC 弦对向 ABC 弧. XZ 边对向 XYZ 角. =>illus 见插图.

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