Answer:
4/5.
Step-by-step explanation:
The right triangle with this angle in it has sides 3, 4 and 5. ( 5^2 = 3^2 + 4^2).
So as sin∅ = 3/5, the opposite side to angle ∅ is 3 , the hypotenuse is 5 and the adjacent side must be 4 units long.
So cos∅ = adjacent side/hypotenuse = 4/5.
