If tan B=2 what is cos B

Question

In a right triangle <a and <b are acute 

Answer 1

tan=opposite/adjacent

tan=2 or 2/1

in the right triangle the opposite side=2 and the adjacent side=1

the hypotenuse is √(2²)+(1²)=√5

cos=adjacent/hypotenuse

cos=1/√5

cos=1√5/√5√5

cos=√5/5, or 2.23606/5=0.44721