Solution:
We know that a pyramid is a polyhedron with a polygon as its base and triangle lateral sides.Let us check for each option.
Check for option (1) An equilateral triangle cannot form a pyramid.
Check for option (2) A pyramid can be formed by a square having the same side length as a triangle.
Check for option (3) A pyramid cannot be formed by 2 squares with the same side length as a triangle.
Check for option (4) A pyramid cannot be formed by 2 equilateral triangles with the same side length as a triangle.
The correct option is (2).
