Geometryhard · Past Paper
The length of a transverse common tangent to two circles of radii 8 cm and 2 cm with centers 13 cm apart is:
Asqrt(69) cm
Bsqrt(105) cm
C12 cm
Dsqrt(165) cm
✓ Correct Answer: B — sqrt(105) cm
Length = sqrt(d^2 - (r1+r2)^2) = sqrt(13^2 - 10^2) = sqrt(169 - 100) = sqrt(69)? Recheck formula. Transverse uses r1+r2. 13^2 - (8+2)^2 = 169 - 100 = 69. sqrt(69).
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