Draw a triangle ABC with the given specifications, AB=5 cm, AC = 6 cm and ∠BAC = 45∘.
Draw perpendicular bisectors of sides AB and AC, they meet at O. Join OB.
So, O is the centre and OB is the radius of the circumcircle of △ABC.
From the above constructions, we see that the circumradius of △ABC is 2.8 cm.