Find the missing side lengths, perimeter, and area of triangle ABC on the coordinate plane. All answers should be in simplest radical form, if necessary:

A (-1, 4)
B (-3,2)
C (0,2)

(5 points)
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Side Length AB: Response area

Side Length BC: Response area

Side Length AC: Response area

Perimeter of Triangle ABC: Response area

Area of Triangle ABC: Response area



Note: the formula for area of a triangle is A=bh2
, where b is the length of the base (BC) and h is the height from side BC to point A.

1 answer

To find the missing side lengths, perimeter, and area of triangle ABC given the points A (-1, 4), B (-3, 2), and C (0, 2), we'll follow these steps:

Step 1: Calculate the side lengths

Side Length AB: Using the distance formula \( d = \sqrt{(x_2 - x_1)^2 + (y_2 - y_1)^2} \):

  • A(-1, 4) and B(-3, 2): \[ AB = \sqrt{((-3) - (-1))^2 + (2 - 4)^2} = \sqrt{(-2)^2 + (-2)^2} = \sqrt{4 + 4} = \sqrt{8} = 2\sqrt{2} \]

Side Length BC:

  • B(-3, 2) and C(0, 2): \[ BC = \sqrt{(0 - (-3))^2 + (2 - 2)^2} = \sqrt{(3)^2 + (0)^2} = \sqrt{9} = 3 \]

Side Length AC:

  • A(-1, 4) and C(0, 2): \[ AC = \sqrt{(0 - (-1))^2 + (2 - 4)^2} = \sqrt{(1)^2 + (-2)^2} = \sqrt{1 + 4} = \sqrt{5} \]

Step 2: Calculate the perimeter of triangle ABC

\[ \text{Perimeter} = AB + BC + AC = 2\sqrt{2} + 3 + \sqrt{5} \]

Step 3: Calculate the area of triangle ABC

Using the formula \( A = \frac{1}{2} b h \):

  • Base (BC) = 3
  • Height (h) is the y-distance from point A to line BC (which is y = 2). The height is the vertical distance from A(4) to line BC(2):
    \[ h = 4 - 2 = 2 \] \[ \text{Area} = \frac{1}{2} \times 3 \times 2 = 3 \]

Final Responses

  • Side Length AB: \( 2\sqrt{2} \)
  • Side Length BC: \( 3 \)
  • Side Length AC: \( \sqrt{5} \)
  • Perimeter of Triangle ABC: \( 2\sqrt{2} + 3 + \sqrt{5} \)
  • Area of Triangle ABC: \( 3 \)

You can now insert these responses accordingly.