Since triangles ΔABC and ΔCDA are congruent by the Hypotenuse-Leg (HL) Theorem, we can deduce that the corresponding sides of the triangles are equal.
From the information given, we have:
- AC = 84 m (hypotenuse in ΔABC)
- AD = 85 m (hypotenuse in ΔCDA)
For right triangles, if AC corresponds to AD, then we can assume that:
- Side AB corresponds to side CD
- Side BC corresponds to side DA
Given that AC and AD are the hypotenuses of congruent triangles, the lengths of sides AB and CD will also be equal.
Since ΔABC is congruent to ΔCDA, it follows that:
\[ AB = CD \]
We still need to figure out how to relate AB or CD to AC and AD. However, since the problem does not specify the angles or other sides, we can only ascertain that the triangles are congruent.
Since the HL theorem gives us equality of the corresponding sides, the relationship between the legs of both triangles must hold. Since we don't have specific values for AB or CD, we cannot directly determine the length of BA without additional context or values.
However, if we analyze the options:
- The values provided — 27 m, 15 m, 22 m, and 13 m — suggest possible lengths for the sides.
But we can assume that because of HL theorem's nature, in right triangles, typically one leg (let's say AB from ΔABC) would be shorter than the hypotenuse (which is AC), and from the given leg lengths generally a shorter length often leads to 15m or 22m, so looking more closely, since the sticking point of clarity is absent, we'll consider the average of possible leg lengths.
Since the lengths hint suggests:
- The best option, with the consideration of right triangle geometry, is 15 m (given common leg lengths intersect with hypotenuse lengths, rounded to slight estimations).
Therefore, it appears the most reasonable conclusion, consistent with the options provided, leads us to the answer:
15 m (from triangle properties applied under HL reasoning).