Solution:

Steps to construct:

Step 1: Consider a point O on a line, with center O, and radius 3cm, draw a circle.

Step 2: Extend its diameters on both sides and cut off OP = OQ = 7cm.

Step 3: Mark the mid-points of OP and OQ as M and N respectively.

Step 4: With Centers M and N and OP and OQ as diameters, draw circles which intersect the given circle at A, B and C, D respectively.

Step 5: Join PA, PB, QC, QD. Hence, PA, PB and QC, QD are the required tangents.