Question

what shape is the cross-section of the cone when sliced perpendicular to its base through the vertex?
a. rectangle
b. triangle
c. circle
d. square

Explanation:

A cone has a circular base and a vertex. Slicing it perpendicular to the base through the vertex creates a cross - section with two equal slant sides (from the vertex to the base's edge) and a base side (the diameter of the circular base). This shape is a triangle. A rectangle and square have four sides, and a circle is the base shape, not the cross - section here.

Answer:

B. Triangle