1. **Stating the problem:**
We have a trapezoid ABCD with BC = 14 cm and CD = 10 cm. Inside it, triangle BFC has an area of 50 square units. We need to find the area of the shaded region, which is triangle FCD.
2. **Understanding the figure and given data:**
- BC = 14 cm (bottom base)
- CD = 10 cm (right side)
- Area of triangle BFC = 50
3. **Key observations:**
- Points B, F, C form triangle BFC.
- Points F, C, D form triangle FCD (the shaded area).
- Since B, C, D are vertices of the trapezoid, and F lies inside, triangles BFC and FCD share side FC.
4. **Using the area formula for triangles:**
The area of a triangle is given by
$$\text{Area} = \frac{1}{2} \times \text{base} \times \text{height}$$
5. **Relating the two triangles:**
Since triangles BFC and FCD share side FC, and points B and D lie on opposite sides of FC, the heights from B and D to FC are proportional to the lengths of BC and CD respectively.
6. **Calculating the ratio of areas:**
The ratio of areas of triangles BFC and FCD is equal to the ratio of their heights from points B and D to line FC.
Given BC = 14 and CD = 10, the ratio of areas is
$$\frac{\text{Area of } BFC}{\text{Area of } FCD} = \frac{14}{10} = \frac{7}{5}$$
7. **Finding the area of triangle FCD:**
Let the area of triangle FCD be $x$. Then
$$\frac{50}{x} = \frac{7}{5} \implies 50 \times 5 = 7x \implies 250 = 7x \implies x = \frac{250}{7} \approx 35.71$$
**Final answer:**
The area of the shaded region (triangle FCD) is approximately **35.71** square units.
Area Shaded Ac3984
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