Find the perimeter of the polygon defined by the coordinates (5, 12), (12, 0), (0, 0), and (-4, 12). (Round to nearest tenth) A) 42.5 units B) 47.5 units C) 52.5 units D) 57.5 units

Mathematics · Middle School · Thu Feb 04 2021

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To find the perimeter of the polygon, we need to calculate the lengths of its sides using the distance formula between two points \((x_1, y_1)\) and \((x_2, y_2)\): \[ \text{distance} = \sqrt{(x_2 - x_1)^2 + (y_2 - y_1)^2} \]

Let's label the points: A = (5, 12) B = (12, 0) C = (0, 0) D = (-4, 12)

Now, we find the distances between consecutive points (sides of the polygon):

AB: \[ \text{distance} = \sqrt{(12 - 5)^2 + (0 - 12)^2} = \sqrt{7^2 + (-12)^2} = \sqrt{49 + 144} = \sqrt{193} \] BC: \[ \text{distance} = \sqrt{(0 - 12)^2 + (0 - 0)^2} = \sqrt{(-12)^2} = \sqrt{144} = 12 \] CD: \[ \text{distance} = \sqrt{(-4 - 0)^2 + (12 - 0)^2} = \sqrt{(-4)^2 + 12^2} = \sqrt{16 + 144} = \sqrt{160} \] DA: \[ \text{distance} = \sqrt{(5 - (-4))^2 + (12 - 12)^2} = \sqrt{9^2} = \sqrt{81} = 9 \]

Now, add these distances together to get the perimeter of the polygon: \[ P = AB + BC + CD + DA \] \[ P = \sqrt{193} + 12 + \sqrt{160} + 9 \]

We can calculate these using a calculator: \[ P \approx 13.9 + 12 + 12.6 + 9 \] \[ P \approx 47.5 \]

Therefore, the perimeter of the polygon is approximately 47.5 units. The correct answer is B) 47.5 units.