1. **Problem Statement:** We have a right-angled triangle ABC with D and E as midpoints of AB and BC respectively. We want to determine which statements are sufficient to find the length of AC.
2. **Given Statements:**
- I. AE = 19
- II. CD = 22
- III. Angle B is a right angle.
3. **Key Points:**
- Since D and E are midpoints, AD = DB and BE = EC.
- Angle B is right angle means triangle ABC is right-angled at B.
4. **Analyzing Statements:**
- Statement III alone tells us angle B is 90°, so by Pythagoras theorem:
$$AC^2 = AB^2 + BC^2$$
- Statement I gives AE = 19. Since E is midpoint of BC, AE is a segment connecting A to midpoint E.
- Statement II gives CD = 22. Since D is midpoint of AB, CD is a segment connecting C to midpoint D.
5. **Using Midpoint Theorem:**
- Segment DE is parallel to AC and DE = 1/2 AC.
- Lengths AE and CD relate to the triangle but do not directly give AC without additional info.
6. **Checking combinations:**
- I and II alone: Knowing AE and CD does not give enough info to find AC.
- III alone: Knowing angle B is right angle allows use of Pythagoras but we need side lengths.
- I and III: Knowing AE and right angle B still lacks direct side lengths.
- II and III: Knowing CD and right angle B can help because CD relates to sides AB and BC.
- All three statements: Combining AE, CD, and right angle B gives enough info to find AC.
**Final conclusion:** Only "All three statements" together are sufficient to determine the length of AC.
**Answer:** All three statements.
Triangle Ac Length D90F45
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