A right triangle has a 90-degree angle.

直角三角形有一个90度的角。

The lines intersect at a 90-degree angle.

这些线以90度角相交。

Bring one leg up to a 90-degree angle and hold.

转动伸展。背部着地平躺，一条腿向上升呈90度，保持住。

Lie flat on your back. Bring one leg up to a 90-degree angle and hold.

背部着地平躺，一条腿向上升呈90度，保持住。

Rotational stretch. Lie flat on your back. Bring one leg up to a 90-degree angle and hold.

转动伸展。背部着地平躺，一条腿向上升呈90度，保持住。

Also, make sure that your screen is at a 90-degree angle to any light source to cut down on glare.

同时，确使你的屏幕对任何光源都保持90度角来减少光的强度。

Relax your arms and let them swing naturally, close to your body at a 90-degree angle when you walk.

放松双臂，自然摆动，步行的时候双臂贴紧身体，与身体形成90度。

Make-up: long edge of lath made according to the actual needs of the 90-degree angle to join together.

拼 版：板条长边根据实际需要做成90度角的企口和凹口来拼接。

Perform quad leg lifts by lying flat on your back on the floor. Bend one knee to a 90-degree angle.

平躺在地板上。一条腿的膝盖弯曲成90度。

That means that the best way to launch a high-altitude projectile is to send it flying at a 90-degree angle to the ground—straight up.

这表明使抛物体能够抛到高处的最好方法就是使它以跟地面成90度的角度抛出，也就是竖直往上抛出。