1. **Problem Statement:** We are given a triangle with points A, B, C, and D inside it. We know that $\angle DAC = \angle BAD$ and the lengths $AC = 4.6$, $CD = 2.5$, and $AB = 6.8$. We need to find the length of $\overline{BD}$ rounded to one decimal place.
2. **Key Insight:** Since $\angle DAC = \angle BAD$, point D lies on the angle bisector of $\angle BAC$. By the Angle Bisector Theorem, the angle bisector divides the opposite side into segments proportional to the adjacent sides.
3. **Angle Bisector Theorem:** If $D$ lies on $BC$ such that $AD$ bisects $\angle BAC$, then
$$\frac{BD}{DC} = \frac{AB}{AC}$$
4. **Apply the theorem:** Substitute the known values:
$$\frac{BD}{2.5} = \frac{6.8}{4.6}$$
5. **Solve for $BD$:**
$$BD = 2.5 \times \frac{6.8}{4.6}$$
Calculate the fraction:
$$\frac{6.8}{4.6} \approx 1.4783$$
Multiply:
$$BD \approx 2.5 \times 1.4783 = 3.6958$$
6. **Round the answer:**
$$BD \approx 3.7$$
**Final answer:** The length of $\overline{BD}$ is approximately **3.7** units.
Angle Bisector Length Ff13Eb
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