Concave polygon
n. 凹多边形
🧩 词语组成解析
concave
['kɔn'keiv]
n. 凹面，成凹形;
adj. 凹的;
vt. 使成凹形;
polygon
['pɔligən]
n. 多边形，多角形;龟裂状;
🗣️ 情景例句
The teacher flunked him in geography.
老师给他的地理打不及格。
If it hadn't been for your help, we would never have finished it.
如果没有你的帮助，我们永远完不成任务。
You'd better go to bed earlier tonight, if you can.
如果可能，你今晚最好早点儿睡觉。