Can someone explain or help me out

The bird has to fly 7.5 m

Step-by-step explanation:

Please see diagram in attached image.

Notice that there is a right angle triangle that defines the situation, and you know two elements of such triangle;

1) one acute angle (), and

2) the side opposite to that angle.

What you need to find is the side adjacent to the angle, which is what the bird needs to fly horizontally to be above the fish. We named that "x".

The trig function that relates such triangle elements is the tangent:

which rounded to the nearest tenth is: 7.5 m

9 x 8 divided by (5-3)=36