a.

Let the vertical component of the force be .

Magnitude of the resultant force be .

The direction of Irwins resultanr force is .

The horizontal component of the force is .

Draw a right triangle for the given data :

Find the vertical component of the force, by using the tangent ratio.

From the above diagram :

Thus, the vertical component of the force is about .

b.

Find magnitude of the resultant force,   by using the cosine ratio.

From the above diagram :

Thus, the magnitude of the resultant force is about .

a.

The vertical component of the force is about .

b.

The magnitude of the resultant force is about .