51317810
Four lines enclose a parallelogram:
\(f(x) = 2\)
\(g(x) = -3\)
\(h(x) = x + 1\)
\(k(x) = x - 4\)
Find the area of the enclosed parallelogram.
Hints
- Identify the pairs of parallel lines first.
- Find the vertices by intersecting one line from each parallel pair.
- What is the vertical distance between the two horizontal lines?
- Use the parallelogram area formula once you know a base and its corresponding height.
Solution
1. Find the vertices from pairwise intersections. From \(2 = x + 1\), \(f\) and \(h\) meet at \((1, 2)\). From \(2 = x - 4\), \(f\) and \(k\) meet at \((6, 2)\). From \(-3 = x - 4\), \(g\) and \(k\) meet at \((1, -3)\). From \(-3 = x + 1\), \(g\) and \(h\) meet at \((-4, -3)\).
2. The horizontal side from \((1, 2)\) to \((6, 2)\) has length \(6 - 1 = 5\).
3. The perpendicular height is the vertical distance between \(y = 2\) and \(y = -3\), which is \(2 - (-3) = 5\).
4. Therefore, the area is \(A = 5 \cdot 5 = 25\) square units.
Answer
\(25\) square units
