A component of an object moving at a certain velocity can be split into its x and y components (sometimes there is a z component too, but in the case of a question like this, we can imagine the plane the helicopter is travelling in to be 2 dimensions).
Therefore, we can draw a triangle - the hypotenuse having length 86 and being 35 degrees from the ground.
Since the angle ACB (assuming A to be bottom left and B to be top) is a right angle, we can now work with trigonometry:
Sinx = opp/hyp and Cosx = adj/hyp which will give us the components of the vector. Substituting the known values into the equations and rearranging:
86Sin(35) = Opp = 49.3km/h
86Cos(35) = Adj = 70.4km/h
Therefore, the horizontal component (Ax) is 70km/h and the vertical component (Ay) is 49km/h
