Theory:

Rough diagram:
 
1.PNG
 
Step 1: Draw the \(ΔABC\) with the given measurements.
 
2.PNG

Step 2: Construct the perpendicular bisector of any two sides (\(AC\) and \(BC\)) and let them meet at \(S\) which is the circumcenter.
 
3.PNG

Step 3: \(S\) as centre and \(SA = SB = SC\) as radius, draw the circumcircle to passes through \(A\), \(B\) and \(C\). Circumradius \(=\) \(3.9 cm\).