What is the approximate value of b, rounded to the nearest tenth? use the law of sines to find the answer. triangle a b c is shown. angle c a b is 66 degrees and angle a b c is 76 degrees. the length of a b is 3 and the length of a c is b. law of sines: startfraction sine (uppercase a) over a endfraction = startfraction sine (uppercase b) over b endfraction = startfraction sine (uppercase c) over c endfraction 1.9 units 4.7 units 5.0 units 5.7 units