Can someone help me solve this question?
1 Answer
The figure also has at least one rectangular cross section.
Explanation:
We shall try to come up with a counter-example for each option listed.
The circular cross sections are congruent.
If the 3D object was a skewed cylinder, it would have congruent circular cross sections too. This option is not enough.
The figure also has at least one rectangular cross section.
A cylinder indeed would have infinitely many rectangular cross sections perpendicular to the circular cross sections. But more importantly, no other 3D object with circular cross sections can have rectangular cross sections too. This is our answer.
The centres of the circular cross sections lie on a line.
A cone would also have the centres of its circular cross sections lie on a line; so would a skewed cylinder. This is not enough information.
The circular cross sections are similar but not congruent.
All circles are similar; if the cross sections are not congruent, then the 3D object must be a dome or cone-like shape. It cannot be a cylinder; all its circular cross sections are congruent.
By the process of elimination, we have our answer: The figure also has at least one rectangular cross section.
