Teorema lui Pitagora=>AC la 2 + AB la 2= BC la 2=> AC la 2+ 18 la 2= 30 la 2=>
AC la 2+324=900=> AC la 2=576=>
AC=√576= 24
sinB= AC/BC=24/30=4/5
sinC=AB/BC=18/30=3/5
cosB=AB/BC=18/30=3/5
cosC=AC/BC=24/30=4/5
tgB=AC/AB=24/18=4/3
tgC=AB/AC=18/24=3/4
ctgC=AC/AB=4/3