` DeltaABC` में , a = 125, b=62 और c = 123, तो sin B का मान ज्ञात कीजिए ।

Explanation

a= 125 , b = 62 ,c = 123
` :. 2s = a+b+c`
` = 125 + 62+ 123` ltBrgt ` = 310`
` s= 155`
अब ` sin . B/2 = sqrt(((s-a)(s-c))/(ac))`
` sqrt(( (155-125)(155-123))/(125 xx 123 )`
` = sqrt((30xx 32)/(125xx123))`
और ` cos. B/2 = sqrt((s(s-b))/(ac))= sqrt((155 xx (155 - 62))/(125 xx 123 ) )`
` = sqrt((155xx 93)/(125 xx 123) )`
` :. sin B = 2 sin . B/2 cos. B/2 `
` = 2 sqrt((30xx 32)/(125 xx 123)xx (155xx93)/(125xx123))`
` = (2 xx 3750 ) / ( 125 xx 123) = 496/1025`