plz solve the following problems....

Asked by jeffladebo | 1st Oct, 2015, 11:15: PM

Expert Answer:

17. 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.
L e t space x space a n d space y space b e space t h e space c o minus i n t e r i r o r space a n g l e s. W e space k n o w space t h a t space c o 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 u s comma space x plus y equals 180 degree... left parenthesis 1 right parenthesis A l s o space g i v e n space t h a t space x colon y equals 3 colon 2 rightwards double arrow x over y equals 3 over 2 rightwards double arrow x equals fraction numerator 3 y over denominator 2 end fraction... left parenthesis 2 right parenthesis S u b s t i t u t i n g space t h e space v a l u e space o f space x space f r o m space e q u a t i o n space left parenthesis 2 right parenthesis space i n space e q u a t i o n space left parenthesis 1 right parenthesis comma space w e space h a v e comma fraction numerator 3 y over denominator 2 end fraction plus y equals 180 degree rightwards double arrow fraction numerator 3 y plus 2 y over denominator 2 end fraction equals 180 degree rightwards double arrow fraction numerator 5 y over denominator 2 end fraction equals 180 degree rightwards double arrow 5 y equals 360 degree rightwards double arrow y equals fraction numerator 360 degree over denominator 5 end fraction rightwards double arrow y equals 72 degree S u b s t i t u t i n g space t h e space v a l u e space y equals 72 degree space i n space e q u a t i o n space left parenthesis 1 right parenthesis comma space w e space h a v e comma x plus 72 degree equals 180 degree rightwards double arrow x equals 180 degree minus 72 degree equals 108 degree T h u s comma space t h e space c o minus i n t e r i o r space a n g l e s space a r e space 108 degree space a n d space 72 degree
19. F i r s t space p l o t space t h e space p o i n t space A open parentheses negative 2 comma negative 2 close parentheses space o n space a space g r a p h. C o n s i d e r space t h e space f o l l o w i n g space g r a p h.
W h e n space w e space r e f l e c t space t h e space p o i n t space A space i n space x minus a x i s comma space x minus a x i s space w i l l space b e space t h e space m i r r o r space l i n e space a n d space h e n c e space t h e space x minus c o o r d i n a t e w i l l space r e m a i n space s a m e space a n d space y space c o o r d i n a t e space w i l l space b e space t h e space p o s i t i v e space c o o r d i n a t e space o f space t h e space p o i n t space A. T h u s comma space t h e space p o i n t space B space w i l l space b e comma space B identical to open curly brackets negative 2 comma 2 close curly brackets C o n s i d e r space t h e space f o l l o w i n g space g r a p h.
W h e n space w e space r e f l e c t space t h e space p o i n t space A space i n space y minus a x i s comma space y minus a x i s space w i l l space b e space t h e space m i r r o r space l i n e space a n d space h e n c e space t h e space y minus c o o r d i n a t e w i l l space r e m a i n space s a m e space a n d space x space c o o r d i n a t e space w i l l space b e space t h e space p o s i t i v e space c o o r d i n a t e space o f space t h e space p o i n t space A. T h u s comma space t h e space p o i n t space C space w i l l space b e comma space C identical to open curly brackets 2 comma negative 2 close curly brackets C o n s i d e r space t h e space f o l l o w i n g space g r a p h.
F r o m space t h e space a b o v e space g r a p h comma space o b s e r v e space t h e space a n g l e space angle B A C. I t space i s space c l e a r space t h a t space space angle B A C equals 90 degree
Kindly post one question per query.

Answered by Vimala Ramamurthy | 2nd Oct, 2015, 10:34: AM