Two circles of radii 8 cm and 3 cm, respectively, are 13 cm apart. AB is a direct common tangent touch to both the circles at A and B respectively then the length of AB is
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 12 cm
Formula used
Direct common tangent = √ [(Center distance)2 - (Difference in radius of both circles)2]
Given
Center distance = 13 cm
The radius of both circles = 8 cm and 3 cm
Calculation
Direct common tangent = √ [132 - (8 - 3)2]
= √ 169 - 25 = √ 144 =12 cm