Two equal forces each of magnitude 34N act on a body. Calculate the magnitude and direction of the resultant if the angle between them is 120°.

We use the formula for the resultant of two forces:

$$R = \sqrt{F_1^2 + F_2^2 + 2F_1F_2 \cos \theta}$$

Substitute the given values:

$$R = \sqrt{(34 \text{ N})^2 + (34 \text{ N})^2 + 2(34 \text{ N})(34 \text{ N}) \cos(120^\circ)}$$

Since $\cos(120^\circ) = -0.5$:

$$R = \sqrt{34^2 + 34^2 + 2 \times 34^2 \times (-0.5)}$$ $$R = \sqrt{34^2 + 34^2 - 34^2}$$ $$R = \sqrt{34^2}$$ $$R = 34 \text{ N}$$

When two forces of equal magnitude act on a body, their resultant force bisects the angle between them.
The angle between the forces is $120^\circ$.
Therefore, the direction of the resultant force will be half of this angle relative to either force.

$$\text{Direction} = \frac{120^\circ}{2} = 60^\circ$$

The magnitude of the resultant force is $\boxed{34 \text{ N}}$ and its direction is $\boxed{60^\circ \text{ from either force}}$.