15)ABC triunghi dreptunghic 
m(<A)=90 grade
AB=15 cm
AD=12 cm
D€BC
_________
BC,AC,sin C,cos C,tg B,ctg B?

16)ABC triunghi dreptunghic
m(<A)=90 grade
m(<B)=30 grade
AB=18
√3
AD perpendicular BC
D€(BC)
___________
AC,BC,inaltimea AD?