Cos(A) will be 3/5 Cos(A) is adjacent/hypotenuse. So here we have sin(A)=opp/hyp which is 4/5 and tan(A)=opp/adj which is 4/3. So cos(A) is adj./hyp and knowing the previous 2 terms of sin(A) and cos(A), you can go ahead and find Cos(A). So cos(A) is 3/5
