Engineering Board Exam Reviewer · Circles: Chords, Tangents and Secants · medium
Two circles of radii 8 and 3 touch each other externally. Find the length of their common external tangent.
- 11
- 5
- 4.9
- 9.8
Answer
D. 9.8
Solution
The centers are 8+3=11 apart. t=sqrt(d2-(r1-r2)2)=sqrt(121-25)=sqrt(96)=4 6 9.80.
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