凹おう角かく

noun

concave angle; re-entrant angle

A mathematical term for an angle greater than 180 degrees and less than 360 degrees. Used in geometry.

• 凹おう角かくは180度どより大おおきく360度どより小ちいさい角かくです。

  A concave angle is an angle greater than 180 degrees and less than 360 degrees.