Think of it as trigonometry. Your velocity is the speed combined with the direction; here you have a speed of 8 in a direction 65 degrees (it's unspecified, but most likely we are to understand the angle is 65 degrees above the horizontal).

So, you have a right-angled triangle: The right angle is at B, between the horizontal and the vertical components AB and BC, and the hypotenuse AC is the velocity vector:

C

A B

Since you know the length of AC and the angle at A, and B is a right angle, you can find the vertical component (length BC) by using sin(A) = o/h = BC/AC: