If ABC is congruent with CDS by the HL theorem and AC = 84m and AD=85m how long is BA

If ABC is congruent to CDS by the HL theorem, it means that the hypotenuse (BC) of triangle ABC is congruent to the hypotenuse (DS) of triangle CDS, and the length of one leg (AB) of triangle ABC is congruent to the length of one leg (CS) of triangle CDS.

Since BC is congruent to DS, and we are given AC = 84m, we can determine the length of CS by subtracting AD (85m) from AC:

CS = AC - AD = 84m - 85m = -1m (negative value doesn't make sense here)

So, there seems to be an error in the given information. Without the correct value of CS, we cannot determine the length of BA in this case.