Solution:
Given:
The meaning of circumscribed is drawing a figure around another figure in such a way that the drawn figure touches the outer line or points of the inside figure without intersecting it.
Hence, to circumscribe a cylinder about the candy bar, a circular path is drawn to touch the vertices of the points A, B, and C.
To circumscribe a circle around a triangle, the center of the circle is the point of intersection of the perpendicular bisectors of the sides of the triangle.
The point of intersection common to the bisectors is point D.
Hence, the circle is center D.
Given that AD = 2.5cm, then the radius of the circle = AD = 2.5cm
Hence, the diameter of the circle is;

Therefore, the diameter is 5cm