- A13 cm
- B12 cm
- C6 cm
- D5 cm
Step-by-Step Solution
For circles touching externally the distance between centres is . The direct common tangent has length √ √(169 − 25) = √144 = 12 cm.
Answer: B) 12 cm
Two circles of radii 9 cm and 4 cm touch each other externally. What is the length of their direct (external) common tangent?
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