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A triangle is formed by the straight li...

A triangle is formed by the straight lines `x + 2y - 3 =0 , 3x - 2y + 7 =0 and y+ 1 =0 `, find graphically
the area of the triangle.

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To find the area of the triangle formed by the lines \(x + 2y - 3 = 0\), \(3x - 2y + 7 = 0\), and \(y + 1 = 0\) graphically, we will follow these steps: ### Step 1: Find the Intersection Points of the Lines We need to determine the points where the lines intersect to form the vertices of the triangle. 1. **Intersection of Line 1 and Line 2:** - Line 1: \(x + 2y - 3 = 0\) - Line 2: \(3x - 2y + 7 = 0\) Substitute \(x\) from Line 1 into Line 2: \[ x = 3 - 2y \quad \text{(from Line 1)} \] Substitute into Line 2: \[ 3(3 - 2y) - 2y + 7 = 0 \] \[ 9 - 6y - 2y + 7 = 0 \] \[ 16 - 8y = 0 \implies 8y = 16 \implies y = 2 \] Substitute \(y = 2\) back into Line 1: \[ x + 2(2) - 3 = 0 \implies x + 4 - 3 = 0 \implies x = -1 \] So, the intersection point \(A\) is \((-1, 2)\). 2. **Intersection of Line 2 and Line 3:** - Line 3: \(y + 1 = 0 \implies y = -1\) Substitute \(y = -1\) into Line 2: \[ 3x - 2(-1) + 7 = 0 \implies 3x + 2 + 7 = 0 \implies 3x + 9 = 0 \implies x = -3 \] So, the intersection point \(B\) is \((-3, -1)\). 3. **Intersection of Line 1 and Line 3:** Substitute \(y = -1\) into Line 1: \[ x + 2(-1) - 3 = 0 \implies x - 2 - 3 = 0 \implies x = 5 \] So, the intersection point \(C\) is \((5, -1)\). ### Step 2: Plot the Points The vertices of the triangle are: - \(A(-1, 2)\) - \(B(-3, -1)\) - \(C(5, -1)\) ### Step 3: Calculate the Area of the Triangle The area \(A\) of a triangle formed by vertices \((x_1, y_1)\), \((x_2, y_2)\), and \((x_3, y_3)\) can be calculated using the formula: \[ \text{Area} = \frac{1}{2} \left| x_1(y_2 - y_3) + x_2(y_3 - y_1) + x_3(y_1 - y_2) \right| \] Substituting the coordinates of points \(A\), \(B\), and \(C\): \[ \text{Area} = \frac{1}{2} \left| -1(-1 + 1) + (-3)(-1 - 2) + 5(2 + 1) \right| \] \[ = \frac{1}{2} \left| 0 + 9 + 15 \right| = \frac{1}{2} \left| 24 \right| = 12 \text{ square units} \] ### Final Answer The area of the triangle formed by the given lines is **12 square units**.
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