Find the distance (in cm) between the centres of two circles having radii of 40 cm and 30 cm, respectively, if the length of a/an transverse/indirect common tangent to the two circles is given as 10cm.
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. 80.
Let the distance between the centers be d cm.
Transverse common tangent =
where d is distance between the centers, r1 and r2 are the radius of the two circles.
According to the given question,
⇒ d2 - 4900 = 1500
⇒ d2 = 6400
⇒ d2 = 80