A (-3,-2)

B (4,-2)
C (4,1)
D (-3,1)

Determine the coordinates of rectangle ABCD. Use the coordinates to compute the area of the rectangle.

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1 answer

To determine the coordinates and area of rectangle ABCD, let's first visualize the vertices based on the provided coordinates:

  • Point A: (-3, -2)
  • Point B: (4, -2)
  • Point C: (4, 1)
  • Point D: (-3, 1)

Next, let's check if these points indeed form a rectangle. A rectangle must have opposite sides equal in length and all angles equal to 90 degrees.

Vertices and Lengths:

  1. AB: The distance between points A and B can be calculated as: \[ AB = |x_B - x_A| = |4 - (-3)| = |4 + 3| = 7 \]

  2. BC: The distance between points B and C is: \[ BC = |y_C - y_B| = |1 - (-2)| = |1 + 2| = 3 \]

  3. CD: The distance between points C and D is: \[ CD = |x_D - x_C| = |-3 - 4| = |-7| = 7 \]

  4. DA: The distance between points D and A is: \[ DA = |y_A - y_D| = |-2 - 1| = |-3| = 3 \]

Checking Rectangle Properties:

  • We see that opposite sides are equal: \( AB = CD = 7 \) and \( BC = DA = 3 \).
  • Since there are two pairs of equal opposite sides, and the angles between these sides are 90 degrees (given the coordinate system), it confirms that ABCD forms a rectangle.

Area Calculation:

The area \( A \) of a rectangle can be computed using the formula: \[ \text{Area} = \text{length} \times \text{width} \]

From our calculations:

  • Length (AB or CD) = 7 units
  • Width (BC or DA) = 3 units

Thus, the area is: \[ \text{Area} = 7 \times 3 = 21 \text{ square units} \]

Therefore, the area of rectangle ABCD is \(\boxed{21}\) units square.