The length of the common tangent PQ for two circles touching externally is 16 cm. If the radius (OP) of the bigger circle is 20 cm, then the radius (RQ) of the smaller circle is:

Two concentric circles have radii of 10 cm and 26 cm. Find the length of the chord of the larger circle that is tangent to the smaller circle.​

If the radius  of two circles are 4.5 cm and 3.5 cm and the length of the transverse common tangent is 6 cm, then the distance between the two centers will be:

Two concentric circles form a circular path. The inner and outer circumference of the path are $$56\frac{4}{7}$$ m and $$94\frac{2}{7}$$ m respectively. Find the width of the path.​