Question

In triunghiul ABC se cunosc m(A)=90, AB=4cm si AC=3cm. Aflati cos B

Answer 1

cos (B)=cateta alaturata/ipotenuza
cateta alaturara=AB=4
ipotenuza=BC=radical (AB patrat+AC pătrat)=radical (16+9)=radical (25)=5
cos (B) =4/5

Answer 2

poti merge si cu pitagora => BC^2=AB^2+AC^2 
BC^2=14+9
BC^2=25
BC=radical 25
BC=5

vezi daca este corect la raspunsuri