Two circles touch each other externally. The radius of the first circle with centre A is18 cm. The radius of the second circle with centre B is 8cm.Find the length of their common tangent CD.
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. 24
Formula used
Common tangent = √ (D2 - (R - r)2)
where D = the distance between the center of the given circles
R = the radius of the large circle
r = the radius of the smaller circle
Calculation
Common tangent = √ (262 - (18 - 8)2) = √(676 - 100) = √576 = 24 cm