1. **Problem statement:** We are given a right triangle EDF with a right angle at E, side ED = 7, and angle F = 49°. We need to find the length of side DF.
2. **Identify the sides:** In triangle EDF, angle E is 90°, so side DF is the hypotenuse, side ED is one leg adjacent to angle F, and side EF is the other leg opposite angle F.
3. **Use trigonometric ratios:** Since we know the adjacent side (ED) and want the hypotenuse (DF), we use the cosine function:
$$\cos(\theta) = \frac{\text{adjacent}}{\text{hypotenuse}}$$
Here, $\theta = 49^\circ$, adjacent = 7, hypotenuse = DF.
4. **Set up the equation:**
$$\cos(49^\circ) = \frac{7}{DF}$$
5. **Solve for DF:**
$$DF = \frac{7}{\cos(49^\circ)}$$
6. **Calculate the value:**
$$DF = \frac{7}{\cos(49^\circ)} \approx \frac{7}{0.6561} \approx 10.67$$
7. **Round to the nearest tenth:**
$$DF \approx 10.7$$
**Final answer:**
$$\boxed{10.7}$$
Find Df 492Ac0
Step-by-step solutions with LaTeX - clean, fast, and student-friendly.