Given the points A (3, - 2), B (2, - 5), and C' (4, -5), classify ABC.

(1 point)
• It is a scalene triangle.
• It is an isosceles triangle.
• It is a right triangle.
• It is an equilateral triangle.

1 answer

To classify triangle ABC formed by the points A(3, -2), B(2, -5), and C'(4, -5), we need to calculate the lengths of the sides and determine their relationships.

  1. Calculate the lengths of the sides using the distance formula: \[ \text{Distance} = \sqrt{(x_2 - x_1)^2 + (y_2 - y_1)^2} \]

    • Length of AB: \[ AB = \sqrt{(2 - 3)^2 + (-5 - (-2))^2} = \sqrt{(-1)^2 + (-3)^2} = \sqrt{1 + 9} = \sqrt{10} \]

    • Length of BC: \[ BC = \sqrt{(4 - 2)^2 + (-5 - (-5))^2} = \sqrt{(2)^2 + (0)^2} = \sqrt{4} = 2 \]

    • Length of AC: \[ AC = \sqrt{(4 - 3)^2 + (-5 - (-2))^2} = \sqrt{(1)^2 + (-3)^2} = \sqrt{1 + 9} = \sqrt{10} \]

  2. Compare the lengths of the sides:

    • \(AB = \sqrt{10}\)
    • \(BC = 2\)
    • \(AC = \sqrt{10}\)

    Here, we observe that:

    • \(AB = AC\)
    • \(BC\) is different from \(AB\) and \(AC\).

Since two sides (AB and AC) are equal, triangle ABC is classified as an isosceles triangle.

  1. Check if it is a right triangle: We can check if it forms a right triangle using the Pythagorean theorem. If \(a\) and \(b\) are the lengths of the two shorter sides, and \(c\) is the longest side, then: \[ a^2 + b^2 = c^2 \]

In our case:

  • \(a = AC = \sqrt{10}\)
  • \(b = AB = \sqrt{10}\)
  • \(c = BC = 2\)

Calculating: \[ (\sqrt{10})^2 + (\sqrt{10})^2 = 10 + 10 = 20 \quad and \quad (2)^2 = 4 \]

Since \(20 \neq 4\), it is not a right triangle.

Conclusion: Triangle ABC is an isosceles triangle.