A cone
A cone perhaps
sphere
A cone.
A shape with one corner is a triangle. Yes, I know, technically it has three sides, but it only has one corner. So, there you have it, a triangle is the shape you're looking for.
A circle perhaps or maybe a cone
corner is a point, where more than two plane will intersect. Example: Cube. Rajasekar-Infotech Bangalore.
An ellipse.
The Cone
A cone
A Cone
A circle, ellipse or similar shape.
A cone has one vertex and one edge.