Найдем cos В.
cos B = √(1 - sin^2 В) = √(1 - (7/25)^2) = √(1 - 49/625) = √(625/625 - 49/625) = √(576/625) = 24/25.
tg B = sin B/cos B = (7/25)/(24/25) = 7/25 * 25/24 = 7/24;
Найдем АС.
tg B = АС/ВС;
AC = BC * tg B = 48 * 7/24 = 48/24 * 7 = 2 * 7 = 14.
Найдем cos В.
cos B = √(1 - sin^2 В) = √(1 - (7/25)^2) = √(1 - 49/625) = √(625/625 - 49/625) = √(576/625) = 24/25.
tg B = sin B/cos B = (7/25)/(24/25) = 7/25 * 25/24 = 7/24;
Найдем АС.
tg B = АС/ВС;
AC = BC * tg B = 48 * 7/24 = 48/24 * 7 = 2 * 7 = 14.