1. **State the problem:** We need to find the area of a compound shape made of a rectangle and a right-angled trapezoid and check if Rio's answer of 4.42 cm² is correct.
2. **Convert all measurements to centimeters:**
- Height of rectangle = 19 mm = 1.9 cm
- Width of top side (rectangle width) = 26 mm = 2.6 cm
- Height of trapezoid slant side = 9 mm = 0.9 cm
- Bottom width of trapezoid = 12 mm = 1.2 cm
3. **Calculate the area of the rectangle:**
$$\text{Area}_{rectangle} = \text{height} \times \text{width} = 1.9 \times 2.6 = 4.94\, \text{cm}^2$$
4. **Calculate the height of the trapezoid:**
Since the trapezoid is right-angled, the height is the slant height = 0.9 cm.
5. **Calculate the top width of the trapezoid:**
The top width of trapezoid = total top width - bottom width of trapezoid = 2.6 cm - 1.2 cm = 1.4 cm
6. **Calculate the area of the trapezoid:**
Formula for trapezoid area:
$$\text{Area}_{trapezoid} = \frac{(a + b)}{2} \times h$$
where $a$ and $b$ are the parallel sides, $h$ is the height.
Here,
$$a = 1.4, \quad b = 1.2, \quad h = 0.9$$
Calculate:
$$\text{Area}_{trapezoid} = \frac{(1.4 + 1.2)}{2} \times 0.9 = \frac{2.6}{2} \times 0.9 = 1.3 \times 0.9 = 1.17\, \text{cm}^2$$
7. **Calculate total area:**
$$\text{Total area} = \text{Area}_{rectangle} + \text{Area}_{trapezoid} = 4.94 + 1.17 = 6.11\, \text{cm}^2$$
8. **Compare with Rio's answer:**
Rio's answer is 4.42 cm², which is less than the calculated 6.11 cm².
**Conclusion:** Rio's answer is incorrect. The correct area of the compound shape is $6.11\, \text{cm}^2$.
Compound Shape Area 4E6445
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