Question

There are two circles with centres $c_1\&c_2$ with having radii $3cm$. Distance between their centres is $8cm$.
Length of Direct common tangent is .............. cm

• A. $3$
• B. $4$
• C. $6$
• D. $8$

Answer 1

Answer: (D)

$8$

Length of D.C.T $=\sqrt{d^2-(r_1-r_2{)}^2}$($d$ =distance between 2 centres.)

$=\sqrt{64-(3-3{)}^2}=8$ cm

So, option D is correct.