<h2>
Answer:</h2>
Ellipse---- Diagonal cross section of a cylinder.
Circle---- Cross section parallel to the base of a cone.
Sphere---- Shape created when a semi-circle is rotated around the y-axis.
Great circle---- Diagonal cross section through the widest part of a sphere.
Triangle---- Perpendicular cross section of a cone
<h2>
Step-by-step explanation:</h2>
Ellipse--
It is the plane curve which is obtained when we take a diagonal cross section of the cylinder.
Circle--
We know that when the cross-section of a solid is taken parallel to it's base then the figure so obtained is similar to the base of the solid.
Now we know that the base of a solid is in the shape of a circle.
Hence, when the slicing is done parallel to the base of a cone then we obtain a circle.
Sphere--
A sphere is obtained when we rotate a semi-circle about any line or any axis.
Great Circle--
A great circle is obtained when a plane cuts the sphere diagonally i.e. through it's center.
Triangle--
We know that when a cross section is taken perpendicular to the base of a cone then the cross-section so obtained is a figure similar to the face of a solid.
Hence, the cross-section will be a triangle.
