Function to find the length of the transverse common tangent
static void lengthOfTangent ( double r1 , double r2 , double d ) { Console . WriteLine ( " The ▁ length ▁ of ▁ the ▁ transverse " + " ▁ common ▁ tangent ▁ is ▁ " + Math . Sqrt ( Math . Pow ( d , 2 ) - Math . Pow ( ( r1 + r2 ) , 2 ) ) ) ; }