8,9 |  |

Find the radius of the smallest circle in which a triangle with sides 7, 9, and 12 can be placed.
The given triangle is obtuse.

## Solution

$7^{2}+9^{2}<127^{2}$, therefore the given triangle is obtuse. Consequently, the circle constructed with the largest side of the triangle as its diameter contains the triangle.

## Answer

6.