1. **State the problem:** We have a rectangle ABCD with diagonals AC and BD intersecting at point E. Given that $BD = 4x - 2$, $AC = 5x - 10$, and $m\angle EDA = 39^\circ$, find the length $AE$ and the measure $m\angle EAB$.
2. **Recall properties of rectangles and diagonals:** In a rectangle, the diagonals are equal in length and bisect each other. This means:
$$BD = AC$$
and
$$AE = EC = BE = ED = \frac{AC}{2} = \frac{BD}{2}$$
3. **Set up the equation for the diagonals:**
$$4x - 2 = 5x - 10$$
4. **Solve for $x$:**
$$4x - 2 = 5x - 10$$
$$-2 + 10 = 5x - 4x$$
$$8 = x$$
5. **Find the length of diagonal $AC$ (or $BD$):**
$$AC = 5x - 10 = 5(8) - 10 = 40 - 10 = 30$$
6. **Find $AE$ (half of diagonal $AC$):**
$$AE = \frac{AC}{2} = \frac{30}{2} = 15$$
7. **Find $m\angle EAB$:**
Since $E$ is the midpoint of the diagonals, and $m\angle EDA = 39^\circ$, note that $\angle EDA$ and $\angle EAB$ are congruent because opposite angles formed by intersecting diagonals in a rectangle are equal.
Therefore:
$$m\angle EAB = 39^\circ$$
**Final answers:**
$$AE = 15$$
$$m\angle EAB = 39^\circ$$
Rectangle Diagonals A66640
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