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what isthe justifications for the questionasked in video part 3 in parallel and transversal topic
 
Asked by sanatkothari99 | 25 Jul, 2014, 10:01: PM
answered-by-expert Expert Answer
1. G i v e n space t h a t space x plus 80 space a n d space 5 x space a r e space t h e space c o r r e s p o n d i n g space a n g l e s space f o r m e d space b y space t h e space t r a n s v e r s a l space o f space t w o space p a r a l l e l space l i n e s. S i n c e space t h e space c o r r e s p o n d i n g space a n g l e s space a r e space e q u a l comma space w e space h a v e comma x plus 80 equals 5 x rightwards double arrow 5 x minus x equals 80 rightwards double arrow 4 x equals 80 rightwards double arrow x equals 80 over 4 equals 20 2. space G v i e n space t h a t space 2 x plus 10 space a n d space 86 plus x space a r e space a l t e r n a t e space e x t e r i o r space a n g l e s space f o r m e d space b y space t h e space t r a n s v e r s a l space o f space t w o space p a r a l l e l space l i n e s. S i n c e space t h e space a l t e r n a t e space e x t e r i o r space a n g l e s space a r e space e q u a l comma space w e space h a v e 2 x plus 10 equals 86 plus x rightwards double arrow 2 x minus x equals 86 minus 10 rightwards double arrow x equals 76 3. space G i v e n space s ta t e m e n t space i s : I f space t w o space v e r t i c a l l y space o p p o s i t e space a n g l e s space a r e space e q u a l comma space t h e n space t h e space l i n e s space a r e space p a r a l l e l. W e space n e e d space t o space s a y space w h e t h e r space i t space i s space t r u e space o r space n o t. S i n c e space v e r t i c a l l y space o p p o s i t e space a n g l e s space a r e space f o r m e d space o n l y space w h e n space t h e space l i n e s space a r e space i n t e r s e c t i n g space a n d space h e n c e t h e space t w o space l i n e s space a r e space n o t space p a r a l l e l. H e n c e space t h e space c o r r e c t space o p t i o n space i s space " f a l s e " 4. space space G i v e n space s ta t e m e n t space i s : I f space t r a n s v e r s a l space i s space p e r p e n d i c u l a r space t o space o n e space o f space t h e space l i n e s comma space t h e n space i t space i s space p e r p e n d i c u l a r space t o space o t h e r space l l i n e. W e space n e e d space t o space s a y space w h e t h e r space i t space i s space t r u e space o r space n o t. L e t space t h e space t r a n s v e r s a l space o f space t h e space t w o space p a r a l l e l space l i n e s space i s space p e r p e n d i c u l a r space t o space f i r s t space l i n e. L e t space i t space b e space alpha equals 90 degree L e t space beta space b e space t h e space a n g l e space f o r m e d space b y space t h e space t r a n s v e r s a l space w i t h space t h e space s e c o n d space l i n e. S i n c e space t h e space c o r r e s p o n d i n g space a n g l e s space a r e space e q u a l comma space w e space h a v e comma space alpha equals beta equals 90 degree T h u s comma space i t space i s space c l e a r space t h a t space t h e space t r a n s v e r s a l space l i n e space i s space p e r p e n d i c u l a r space t o space s e c o n d space l i n e. H e n c e space t h e space c o r r e c t i o n space o p t i o n space i s space " T r u e " 5. space G i v e n space s t a t e m e n t space i s : I f space t h e space t r a n s v e r s a l space i n t e r s e c t s space t w o space l i n e s space s u c h space t h a t space p a i r space o f space a l t e r n a t e space i n t e r i o r space a n g l e s a r e space e q u a l space t h e n space l i n e s space a r e space p a r a l l e l space t o space e a c h space o t h e r. W e space n e e d space t o space s a y space w h e t h e r space i t space i s space t r u e space o r space n o t. S i n c e space t h e space a l t e r n a t e space i n t e r i o r space a n g l e s space a r e space e q u a l comma space t h e space c o n s e c u t i v e space i n t e r i o r space a n g l e s space a r e space s u p p l e m e n t a r y. T h a t space i s space t h e space c o r r e s p o n d i n g space a n g l e s space a r e space e q u a l. H e n c e space t h e space l i n e s space a r e space p a r a l l e l.
Answered by Vimala Ramamurthy | 31 Jul, 2014, 10:54: AM

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