trilete rays

例句：

1. 1.The triangle is a classic shape with three right angles.
   三角形是一个经典的具有三个直角的图形。
2. 2. The triangle has three sides and three angles.
   三角形有三个边和三个角。
3. 3.The triangle is the only shape that can be divided into two equal parts.
   三角形是唯一可以分成两个相等部分的形状。