What is the shape of a cross section that is parallel to the base of a cube?

B) ΔABC and ΔA′B′C′ are congruent.

Step-by-step explanation:

Given

See attachment for and

Required

Determine the relationship between both triangles

The single line on all sides of both triangles implies that the sides of the triangles are equal

i.e.

--- sides

Similarly, the same mark on the three angles of both triangles means that the angles of the both triangles are equal

i.e.

--- angles

Hence, both triangles are congruent