Tan O = opposite side / adjacent side t = 40 / 9
We can find the hypotenuse by using Pythagoras:-
h^2 = 40^2 + 9^2 = 1681
h = sqrt 1681 = 41
so sin O = 40/41 and cos O = 9/41
sin 2O = 2 sin O cos O = 2 * 40/41 * 9/41 = 720/1681 = 0.43 to the nearest hundredth (answer).