Find the perimeter of an equilateral triangle whose centerline is 4 cm.

An equilateral triangle is a triangle in which all sides and all angles are the same. The middle line of a triangle connects the midpoints of its two sides. The midline of a triangle is half the base of the triangle. So all sides of the triangle are equal:

a = 4 * 2 = 8 cm.

The area of an equilateral triangle is found by the formula:

S = a²√3 / 4;

S = 8²√3 / 4;

S = 64√3 / 4;

S = 16√3 cm².

Answer: 16√3 cm²