The answer depends on the angle at which the axis of the cone intersects the cross-sections.
cone
cone
No because it would be smaller.
The cross section will be a triangle with base 2 feet and a vertical height of 9 feet.
The vertical cross section of a right vertical cone is a triangle if that cross section is taken from the vertex. Any other vertical cross section will reveal a hyperbola (with endpoints on the base of the cone). A link can be found below.
Circle
The answer depends on the angle at which the axis of the cone intersects the cross-sections.
If it a right cone then it is a circle, otherwise an ellipse.
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Circle
A circular cross-section.
Circular when looking up at it
cone
By definition, the circular cross-section of a cone changes linearly in width as you go along its axis. By definition, the cross-section of a prism is constant along its axis. So, by definition, a cone prism is an impossible shape.
For a right cone, it is a hyperbola which becomes and isosceles triangle when the section passes through the apex.
The strongest shape in nature is the triangle. A traffic cone has a cross section of a triangle. This would give it strength especially when knocked into by the traffic.