P AND Q ARE POINTS ON THE SIDES AB AND AC RESPECTIVELY OF A TRIANGLE ABC.  IF AP=3CM   AND   PB=12CM    AND PQ PARALLEL BC FIND THE LENGTH OF PQ.  
 

Asked by dalbirgolagarh | 17th Aug, 2015, 09:27: AM

Expert Answer:

C o n s i d e r space t h e space f o l l o w i n g space f i g u r e.
G i v e n space t h a t space P Q parallel to B C B y space b a s i c space p r o p o r t i o n a l i t y space t h e o r e m comma space w e space h a v e comma fraction numerator A P over denominator A B end fraction equals fraction numerator P Q over denominator B C end fraction A B equals A P plus P B space space space space space equals 3 plus 12 space space space space space equals 15 space c m T h u s comma space fraction numerator A P over denominator A B end fraction equals fraction numerator P Q over denominator B C end fraction rightwards double arrow 3 over 15 equals fraction numerator P Q over denominator B C end fraction rightwards double arrow 1 fifth equals fraction numerator P Q over denominator B C end fraction rightwards double arrow P Q equals fraction numerator B C over denominator 5 end fraction space c m I f space w e space s u b s t i t u t e space t h e space l e n g t h space o f space B C space i n space t h e space a b o v e space e q u a t i o n comma space w e space g e t space t h e space l e n g t h space o f space P Q.

Answered by Vimala Ramamurthy | 18th Aug, 2015, 08:52: AM