Two circles touch each other externally, having a radius of 12 cm and 8 cm, respectively. Find the length of their common tangent, AB with point A on the bigger circle and B on the smaller circle.
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. cm
Given that
Two circles touch each other externally,
Radius of big circle R = 12 cm
The radius of small circle, r = 8 cm
Formula used
Length of Direct common tangent = √(D2 - (R - r)2)
where, D is the distane between centres of circles
Calculation
D = R + r = 12 + 8 = 20 cm
Length = √(202 - (12 - 8)2) = √(400 - 16) = √384 = 8√6 cm