The perimeter of a regular triangle is 30√3 cm. The computational diameter of the circle circumscribed about this triangle.

An equilateral triangle is a triangle in which all sides are equal. The perimeter of a triangle is the sum of all its sides. Then, knowing the perimeter of an equilateral triangle, it is easy to find its sides. Divide the perimeter by three. So the side of our triangle is: 30√3: 3 = 10√3 centimeters. The radius of the circumscribed circle about an equilateral triangle is found by the formula: (a * √3) / 3, where a is the side of the triangle. Then R = (a * √3) / 3 = (10√3 * √3) / 3 = (10 * 3) / 3 = 10 (centimeters). Therefore, D = 2 * 10 = 20 cm.
Answer: 20 centimeters.