Here's the text written in MathJax:

A sector of a circle with radius \(7.2\) cm that subtends an angle of \(300^\circ\) at the center has an arc length equal to the circumference of the base of the cone.

The arc length is given by the formula \(\text{arc length} = \frac{\text{angle}}{360} \times 2 \times \pi \times \text{radius}\), so in this case, the arc length is \(\frac{300}{360} \times 2 \times \pi \times 7.2 = 12\pi\).

The circumference of the base of the cone is equal to \(2\pi r\), where \(r\) is the radius of the base of the cone. Since the arc length of the sector is equal to the circumference of the base of the cone, we have \(12\pi = 2\pi r\). Solving for \(r\), we get \(r = 6\).

So, the radius of the base of the cone is 6 cm.