An isosceles triangle is inscribed in a semicircle, as shown in the diagram, and it continues to be inscribed as the semicircle changes size. The area of the semicircle is increasing at the rate of 1 cm/sec when the radius of the semicircle is 6 cm. How fast is the perimeter of the semicircle increasing when the radius is 6 cm? Include units in your answer. Round your answer to 3 decimal places. Answer: