Answer: OPTION A.
Step-by-step explanation:
First, in order to solve this exercise, it is important to know the definition of "Cross section".
A Cross-section is defined as the shape obtained when a plane intersects a 3-dimensional figure.
A Regular square pyramid has a square as its base and its faces are four congruent Isosceles triangles.
Therefore, if a plane slices a Square pyramid through the top vertex, theb figure obtained is an Isosceles triangle (which is a triangle that has two sides of equal length).
Then, you can conclude that the options that shows the best description of the cross-section obtained by slicing the given Square pyramid through the top vertex, is the Option A.
