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 ?
Answer & explanation
Correct answer: option 4
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.