正立摆放的圆锥，水平投影是一个圆，另两面投影是三角形。The projection of a cone which is set to upright must be one circle frame and two triangles.
A: 正确
B: 错误
A: 正确
B: 错误
举一反三
- 正立摆放的圆锥，水平投影是一个圆，另两面投影是三角形。The projection of a cone which is set to upright must be one circle frame and two triangles.
- 正立摆放的圆锥，水平投影是一个圆，另两面投影是三角形。The projection of a cone which is set to upright must be one circle frame and two triangles. A: 正确 B: 错误
- 四棱锥的投影，有两面投影外轮廓一定是三角形（）。There are two side views having triangles for the projection of a square pyramid. A: 正确 B: 错误
- 四棱锥的投影，有两面投影外轮廓一定是三角形（）。There are two side views having triangles for the projection of a square pyramid.
- 两个视图为三角形，一面视图是圆的基本体是什么图形？What is the shape of the object two views that are both triangles and one view is a circle frame? A: 圆台 frustum of a cone B: 圆柱 cylinder C: 圆锥cone D: 四棱锥frustum of a pyramid