The distance between the centres of two circles of radii 7 cm and 5 cm is 15 cm. Find the length of the transverse common tangent to these circles.
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. 9 cm.
r1 = 7 cm and r2 = 5 cm
Distance between their centers (d) = 15 cm
Length of the transverse common tangent (L) = √[d2 - (r1 + r2)2]
= √[152 - (7 + 5)2]
= √(225 - 122)
= √(225 - 144)
= √81
= 9 cm
Therefore, the length of the transverse common tangent to these circles is 9 cm.