বলয়াকৃতিবলয়ী প্ৰাণী
বলয়ী নল (Assamese)
বলয়ী নল (Assamese)
1. GeometryIn geometry, a torus (pl.: tori or toruses) is a surface of revolution generated by revolving a circle in three-dimensional space one full revolution about an axis that is coplanar with the circle. The... from wikipedia.org