Question:
What is the distance between two parallel tangents of a circle of radius 4 cm?
Solution:
Two parallel tangents can exist at the two ends of the diameter of the circle. Therefore, the distance between the two parallel tangents will be equal to the diameter of the circle. In the problem the radius of the circle is given as 4 cm. Therefore,
Diameter = 
Diameter = 8 cm
Hence, the distance between the two parallel tangents is 8 cm.