1. **Problem Statement:** We are given a pentagon ABCDE with the following properties:
- AB = 7 cm
- BC = 6 cm
- AB and BC are perpendicular
- AB and DC are equal and parallel
- Area of the pentagon = 54 cm^2
- The pentagon has exactly one line of symmetry
We need to find the dimensions or coordinates to complete a labelled drawing of the pentagon.
2. **Understanding the problem:**
- Since AB and BC are perpendicular, ABC forms a right angle at B.
- AB and DC are equal and parallel, so DC = 7 cm and DC is parallel to AB.
- The pentagon has one line of symmetry, which suggests a vertical or horizontal axis of symmetry.
3. **Approach:**
- Place point A at the origin (0,0).
- Since AB = 7 cm and vertical, let B be at (0,7).
- BC = 6 cm and perpendicular to AB, so C is at (6,7).
- Since DC is parallel and equal to AB, DC is vertical and 7 cm long.
- Let D be at (6,y), and E at (x,y) to complete the pentagon.
4. **Calculate coordinates of D and E:**
- Since DC is vertical and equal to AB, D is at (6,7 - 7) = (6,0).
- The pentagon is symmetric, so E is at (x,0) with x to be found.
5. **Calculate area:**
- The pentagon can be divided into a rectangle ABED and a triangle BCD.
- Rectangle ABED has width $x$ and height 7.
- Triangle BCD has base BC = 6 and height 7.
6. **Area formula:**
$$\text{Area} = \text{Area of rectangle} + \text{Area of triangle} = 7x + \frac{1}{2} \times 6 \times 7 = 7x + 21$$
7. **Given area:**
$$7x + 21 = 54$$
8. **Solve for $x$:**
$$7x = 54 - 21 = 33$$
$$x = \frac{33}{7} \approx 4.71$$
9. **Coordinates:**
- A (0,0)
- B (0,7)
- C (6,7)
- D (6,0)
- E (4.71,0)
10. **Conclusion:**
The pentagon ABCDE with these coordinates satisfies all conditions including the area and symmetry.
Final answer: $x = \frac{33}{7}$ cm approximately 4.71 cm for point E's x-coordinate.
Pentagon Area 46F73A
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