What is the area of rectangle ABCD?

coordinate plane with rectangle ABCD at A 0 comma negative 1, B 0 comma 4, C 4 comma 4, and D 4 comma negative 1

16 square units
18 square units
20 square units
25 square units

1 answer

To find the area of rectangle ABCD, we can use the coordinates of its vertices:

  • A(0, -1)
  • B(0, 4)
  • C(4, 4)
  • D(4, -1)

First, we need to determine the lengths of the sides of the rectangle.

  1. Length of AB and CD (vertical sides):

    • The y-coordinates of points A and B are \(y_A = -1\) and \(y_B = 4\).
    • The length of AB (or CD) is calculated as:
      \[ |y_B - y_A| = |4 - (-1)| = |4 + 1| = 5 \text{ units} \]
  2. Length of BC and AD (horizontal sides):

    • The x-coordinates of points B and C are \(x_B = 0\) and \(x_C = 4\).
    • The length of BC (or AD) is calculated as:
      \[ |x_C - x_B| = |4 - 0| = 4 \text{ units} \]

Now we can calculate the area of the rectangle using the formula: \[ \text{Area} = \text{Length} \times \text{Width} \] Substituting the lengths we found: \[ \text{Area} = 5 \times 4 = 20 \text{ square units} \]

Therefore, the area of rectangle ABCD is 20 square units.