a)
cosB=AB/BC=0.8
AB/10=0.8 => AB=8
Aplicand teorema lui Pitagora AC^2=BC^2-AB^2=100-64=36 => AC=6
tgC=sinC/cosC=AB/BC*BC/AC=AB/AC=8/6=4/3
b) ctgB=AB/AC => 2.4=5/AC => AC=25/12
Aplicand teoremla lui Pitgora => BC^2=25+625/144=4225/144 => BC=65/12
c) ctgC=AC/AB => 0.75=3/AB => AB=4
Aplicand teorema lui Pitagora BC=5 (3, 4, 5 sunt si numere pitagorice)