Solution:
Steps to construct:
Step 1: Draw a line segment AB = 6cm.
Step 2: Draw its perpendicular bisector bisecting it at point O.
Step 3: With center O and radius OB, draw a circle.
Step 4: Extend AB to point P such that OP = 5cm.
Step 5: Draw its perpendicular bisector intersecting it at point M.
Step 6: With center M and radius OM, draw a circle which intersects the given circle at T and S.
Step 7: Join OT, OS, PT and PS. Hence, PT and PS are the required tangents to the given circle.
Step 8: On measuring each tangent is 4cm long. PT = PS = 4cm.