trilateral

In geometry class, we learned that a trilateral is simply a three-sided polygon.

在几何课上，我们学到三边形就是有三条边的多边形。

The student drew a trilateral on the board and labeled each of its three sides.

那个学生在黑板上画了一个三边形，并标出了它的三条边。

A trilateral has three angles as well as three sides.

三边形除了有三条边，还有三个角。