In the adjoining figure I and II, are circles with P and Q respectively, The two circles touch each other and have common tangent that touches them at points R and S respectively. This common tangent meets the line joining P and Q at O. The diameters of I and II are in the ratio 4 : 3. It is also known that the length of PO is 28 cm.

Find the length of SO 

Asked by rushabhjain.avv | 1st Apr, 2019, 07:49: AM

Expert Answer:

begin mathsize 16px style OP over OQ equals PR over QS equals 4 over 3
OP equals 28
OQ equals 21
PQ equals OP minus OQ equals 7
PQ over OQ equals 7 over 21 equals 1 third
PR plus QS equals PQ equals 7
RP over QS equals 4 over 3
QS equals 3
SO equals square root of OQ squared minus QS squared end root equals square root of 21 squared minus 3 squared end root equals 12 square root of 3 straight a end root end style

Answered by Sneha shidid | 1st Apr, 2019, 09:47: AM