incident angle of the entering ray

例句：

1. 1. The incident angle of the light iscrucial for determining its direction.
   光的入射角对于确定其方向至关重要。
2. 2. Inastronomy, the incident angle ofa star's light can be usedto measure its distance from Earth.
   在天文学中，可以通过测量恒星光的入射角来测量它离地球的距离。
3. 3. The engineer calculated the incident angle ofthe beam to optimize the lighting effect.
   工程师计算了光束的入射角以优化照明效果。