An equilateral triangle of side 9 cm is inscribed in a circle. Find the radius of the circle.

Explanation

To find the radius of the circle in which an equilateral triangle of side 9 cm is inscribed, we can follow these steps:

### Step 1: Understand the Geometry
An equilateral triangle has all sides equal, and when inscribed in a circle, the center of the circle (circumcenter) is equidistant from all three vertices of the triangle.

### Step 2: Draw the Triangle and Circle
Draw an equilateral triangle ABC with each side measuring 9 cm. Mark the center of the circle as O, which is also the circumcenter of the triangle.

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