Răspuns:
Explicație pas cu pas:
4a)
AC^2 = BC^2 - AB^2 = 400 - 144 = 256
AC = √256 = 16 cm
sin C = AB/BC = 12/20 = 3/5
cos C = AC/BC = 16/20 = 4/5
tg B = AC/AB = 16/12 = 4/3
ctg B = AB.AC = 12/16 = 3/4
_______________________
5a)
sin C = AB/BC
AB = BC*sin C = 25*3/5 = 15 cm
AC^2 = BC^2 - AB^2 = 625 - 225 = 400
AC = √400 = 20 cm
cos B = AB/BC = 15/25 = 3/5
tg C = AB/AC = 15/20 = 3/4
