1. **State the problem:** We need to find the resultant force of two forces acting at an angle. The first force is 6N, the second force is 4N, and the angle between them is 60 degrees. 2. **Formula used:** The magnitude of the resultant force $R$ when two forces $F_1$ and $F_2$ act at an angle $\theta$ is given by the law of cosines: $$ R = \sqrt{F_1^2 + F_2^2 + 2 F_1 F_2 \cos(\theta)} $$ 3. **Apply the values:** Here, $F_1 = 6$, $F_2 = 4$, and $\theta = 60^\circ$. 4. **Calculate cosine:** $\cos(60^\circ) = 0.5$ 5. **Substitute and simplify:** $$ R = \sqrt{6^2 + 4^2 + 2 \times 6 \times 4 \times 0.5} = \sqrt{36 + 16 + 24} = \sqrt{76} $$ 6. **Final evaluation:** $$ R \approx 8.7178 $$ **Answer:** The resultant force is approximately 8.72 N.