Are the lines perpendicular to each other?

这些直线相互垂直吗？

The left wing dipped until it was perpendicular to the ground.

左翼下垂至与地面成90度角。

Let AB be perpendicular to CD.

设ab垂直于CD。

When a surface is perpendicular to the rays, their intensity is at its maximum.

当表面与射线垂直时，射线的强度最大。

So, it's perpendicular to my curve.

它垂直于曲线。