two circles with radii r1 and r2, r1>r2≥2,touch each othere externally.Find angle between direct common tangents...........
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2 Answers
62again, eureka.. this is to be solved by geometry.
Just try to drop perpediculars.. on the common tangent from the center fo the circle..
This is not very tough.. just try to do this... and then use the geometry of class ix-x!
62
use geometry
r1/L=r1/(L+r1+r2) = sin (θ/2)
r1/L=r1/(L+r1+r2)
L/r1=L/r1 + 1+r2/r1
L(r1-r2)/r1.r2 = (r1+r2)/r1
L = r2(r1+r2)/(r1-r2)
sin (θ/2) = r1(r1-r2)/r2(r1+r2)
Similarly, you can use geometry to find the other angles!
