Question

the diagram shows a cone and its axis of rotation. which type of cross section is formed when the cone is intersected by a plane containing the axis of rotation?

a. a circle
b. an isosceles triangle
c. a parabola
d. an oval

Explanation:

A plane containing the axis of rotation of a cone (which is a line from the apex to the center of the base) will intersect the cone such that the cross - section has two equal sides (the slant heights of the cone) and a base (the diameter of the base of the cone). This shape is an isosceles triangle. A circle is formed when the plane is perpendicular to the axis, a parabola is formed when the plane is parallel to the side of the cone, and an oval is not the shape formed in this case.

Answer:

B. an isosceles triangle