垂直角观测
vertical angle observation
垂直角距离
distance by vertical angle
垂直角位置线
position line by vertical angle
等腰直角棱镜组
isosceles right-angle prism group
等腰直角三角形网
right-triangle irregular network
二维直角管道流动
two-dimensional orthogonal channel flows
两直角球面三角形
birectangular spherical triangle
内螺纹衬塑直角管接头
water supply right angle pipe joint with plastic lining internal thread