noun🔗Share正弦 In a right triangle, the ratio of the length of the side opposite an angle to the length of the hypotenuse."In a right triangle with a 30-degree angle, the sine of that angle is 0.5, meaning the side opposite the angle is half the length of the hypotenuse. "在一个直角三角形中,如果有一个角是30度,那么这个角的正弦值(sine)是0.5,这意味着这个角所对的边长是斜边长度的一半。mathscienceChat with AIVocabulary GamePractice Reading