Given that cos θ=3/5 , the value for tan θ will be obtain as follows:
cos θ=adjacent/ hypotenuse
thus
from the information:
adjacent=3
hypotenuse=5
to obtain the opposite we use Pythagorean theorem,
c^2=a^2+b^2
plugging in the values we get:
5^2=a^2+3^2
a^2=5^2-3^2
a^2=25-9=16
a=4
thus
tan θ=opposite/ adjacent=4/3
