中ちゅう心しん角かく

noun

central angle

Geometry term: the angle formed by two radii of a circle, with the vertex at the center.

• 扇おうぎ形がたの中ちゅう心しん角かくを求もとめる公こう式しきを覚おぼえていますか。

  Do you remember the formula for finding the central angle of a sector?