21 orth b n quadront Find Sin a Solutionsin a 21 29 perpend

Solution

sin a = 21 /29

perpendicular = 21 , hypotenuse = 29

base = sqrt ( 29^2 - 21^2 ) = 20

cos a = - 20 / 29

cos b = 24 / 25

base = 24 , hypotenuse = 25

perpendicular = sqrt ( 25^2 - 24^2 ) = 7

hence, sin b = 7 / 25

sin ( a- b) = sin a cos b - cos a sin b

= 21 / 29 * 24/25 - (-20/29) ( 7/25 )

= 504 / 725 + 140 / 725

= 644/725