A swimmer sets off from one bank. The velocity of the swimmer relative to the water is 1.2 m / s

at 45° to the river banks, as shown in Fig. 1.1.
In the space below, draw a scale diagram to determine the resultant velocity of the swimmer
relative to the river banks. This velocity is the resultant of the two velocities shown on Fig. 1.1.
Label this resultant on your diagram.

Me waiting the actual diagram and answar

What is the velocity of the water?

Also, is the swimmer at 45 deg such that they are swimming against the current or with the current?

If the swimmer is swimming directly across the water stream, and his velocity is at a 45 degree angle, then the stream has to be equal to his veloicty relative to the water.

stream velocity (relative to ground) :1.2
his velocity (relative to stream):1.2

his velocity relative to ground=his velocity relative to stream + stream velocity relativ to ground.
This is true whether or not the direction of the stream, in the end, if he is swimming directly across, he is washed downstream at a 45 degree angle (relative to shore)

To determine the resultant velocity of the swimmer relative to the river banks, we need to draw a scale diagram. Here are the steps to do that:

1. Draw a straight line to represent the river banks. Label it as "River Banks."

2. At one end of the river banks line, draw an arrow pointing towards the other end. Label it as "Swimmer's Velocity Relative to Water." This arrow represents the swimmer's velocity of 1.2 m/s at an angle of 45° to the river banks. Make sure the length of this arrow represents the magnitude (1.2 m/s) of the velocity.

3. At the other end of the river banks line, draw another arrow pointing towards the first end. Label it as "River's Velocity." This arrow represents the velocity of the river, which is usually given in the problem statement. If the problem doesn't provide the river's velocity, you can assume it to be zero or any other value given.

4. To determine the resultant velocity, draw a third arrow from the starting point of the swimmer's velocity arrow towards the ending point of the river's velocity arrow.

5. Label this third arrow as "Resultant Velocity." The length of this arrow represents the magnitude and direction of the resultant velocity.

It's important to note that the scale of the diagram should be chosen appropriately so that you can accurately determine the magnitude and direction of the resultant velocity. The angle between the resultant velocity arrow and the river banks line is the direction of the swimmer's resultant velocity relative to the river banks.