F1 has a magnitude of 9N acting due west, and F2 has a magnitude of 12 N.

I know the magnitude is 15 but I don't know the angle and how to calculate it. I need a lot of help for calculating resultant angles.

I need help please

see related question below.

To calculate the angle of the resultant vector, you can use the concept of trigonometry and vector addition. Let's break down the problem step by step:

Step 1: Draw a diagram:
Start by drawing a coordinate system where you can represent the vectors F1 and F2 according to their directions. Place the tail of the vector at the origin point (0,0) and extend the line in the corresponding direction.

Step 2: Break down the vectors:
Resolve each vector into its horizontal and vertical components using trigonometry. Since the angle is not given, assume the angle of F1 as θ1, and the angle of F2 as θ2. Use appropriate trigonometric functions to calculate the horizontal and vertical components of each vector.

For F1:
Fx1 = F1 * cos(θ1)
Fy1 = F1 * sin(θ1)

For F2:
Fx2 = F2 * cos(θ2)
Fy2 = F2 * sin(θ2)

Step 3: Calculate the resultant vectors:
Add the horizontal and vertical components of F1 and F2 to get the resultant vectors.

Rx = Fx1 + Fx2
Ry = Fy1 + Fy2

Step 4: Calculate the magnitude of the resultant vector:
Use the Pythagorean theorem to find the magnitude of the resultant vector.

R = sqrt(Rx^2 + Ry^2)

Step 5: Calculate the angle of the resultant vector:
Use the inverse tangent function to find the angle of the resultant vector.

θ = atan(Ry / Rx)

Note: Be cautious when using the inverse tangent function, as it provides an angle in radians. If you need the answer in degrees, you will need to convert it by multiplying by (180/π).

By following these steps, you should be able to calculate the angle of the resultant vector.