Xét ABC vuông tại A, có:

\(BC^2=AB^2+AC^2=12^2+35^2=1369\)

\(BC=\sqrt{1369}=37cm\)

\(\cos B=\dfrac{AB}{BC}=\dfrac{12}{37}\)

\(\cot B=\dfrac{AB}{AC}=\dfrac{12}{35}\)

\(\sin B=\dfrac{AC}{BC}=\dfrac{35}{37}\)