Diagonal Bd
1. **Stating the problem:** We have a parallelogram ABCD with sides |AB| = 5 cm, |BC| = 5.5 cm, and angle BAC = 45°.
2. **Understanding the figure:** In parallelogram ABCD, diagonal BD connects vertices B and D. We want to find the length |BD| and determine which inequality range it fits.
3. **Using the law of cosines:** Since ABCD is a parallelogram, opposite sides are equal and adjacent sides form the given angle. We consider triangle ABD with sides AB = 5 cm, AD = BC = 5.5 cm, and angle BAD = 45°.
4. **Apply the law of cosines to find |BD|:**
$$|BD|^2 = |AB|^2 + |AD|^2 - 2 \times |AB| \times |AD| \times \cos(45^\circ)$$
5. **Calculate:**
$$|BD|^2 = 5^2 + 5.5^2 - 2 \times 5 \times 5.5 \times \cos(45^\circ)$$
$$= 25 + 30.25 - 55 \times \frac{\sqrt{2}}{2}$$
$$= 55.25 - 55 \times 0.7071$$
$$= 55.25 - 38.89 = 16.36$$
6. **Find |BD|:**
$$|BD| = \sqrt{16.36} \approx 4.045 \text{ cm}$$
7. **Convert to millimeters:**
$$4.045 \text{ cm} = 40.45 \text{ mm}$$
8. **Compare with given options:**
- a) 75 ≤ |BD| ≤ 79 mm
- b) 53 ≤ |BD| ≤ 57 mm
- c) 95 ≤ |BD| ≤ 99 mm
- d) 70 ≤ |BD| ≤ 74 mm
Our calculated |BD| ≈ 40.45 mm does not fit any of these ranges.
**Conclusion:** None of the given options a), b), c), or d) correctly represent the length of diagonal BD based on the given data.
**Final answer:** |BD| ≈ 40.45 mm, which is outside all provided ranges.