What is the type of two-dimensional solid created by a vertical cross section of the cone that passes through the apex? What is the area of the cross section? What is the type of two-dimensional solid created by a vertical cross section of the cone that passes through the apex? What is the area of the cross section?

The vertical cross of a cone will result as a half cone. The cross surface area will be a triangle. The vertical section is called sagittal section which will cut the object with a vertical line (left to right).

Cross section by default is a cut made look like a horizontal line (top to bottom). In a cone, it will result in a circle and the shape would look like just a cone, but smaller.