Radii of two circles are 11 cm and 3 cm. Distance between their centres is 17 cm. What is the length of the Direct common tangent ?

15 cm

Length of the centers be at P and Q.

ON = Radius of the bigger circle = 11 cm

PM = Radius of the smaller circle = 3 cm

Let MN be the direct common tangent,

According to the formula,

= √(\( {17 }^{2 } \) - \( {(11\; -\; 3) }^{2 } \))

= √(289 - 64)

= 15 cm.

Therefore, length of the direct common tangent is 15 cm.