Question

Use the image to answer the question.

A graph shows quadrant 1 with the x-axis and y-axis ranging from 0 to positive 5. Data points marked are point A at left parenthesis 1 comma 2 right parenthesis, point B at left parenthesis 3 comma 2 right parenthesis, point C at left parenthesis 3 comma 4 right parenthesis, and point D at left parenthesis 1 comma 4 right parenthesis. A line joins points A to B, B to C, C to D, and D to A, forming a rectangle.

Apply the Pythagorean Theorem to find the length of the diagonal of the square. Round your answer to the nearest hundredth, if necessary.

1 answer

To find the length of the diagonal of the rectangle formed by the points A, B, C, and D, we can use the Pythagorean Theorem.

The diagonal of the rectangle can be found by determining the lengths of its sides. From the points provided:

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

Step 1: Find the lengths of the sides of the rectangle.

The length of the horizontal side (AB or CD):

  • The x-coordinates of A and B are 1 and 3 respectively.
  • Length AB = x-coordinate of B - x-coordinate of A = 3 - 1 = 2.

The length of the vertical side (AD or BC):

  • The y-coordinates of A and D are 2 and 4 respectively.
  • Length AD = y-coordinate of D - y-coordinate of A = 4 - 2 = 2.

Step 2: Use the Pythagorean Theorem to find the diagonal (d).

According to the Pythagorean Theorem: \[ d^2 = a^2 + b^2 \] where \( a \) is the length of the horizontal side, and \( b \) is the length of the vertical side.

In this instance, both \( a \) and \( b \) are equal to 2:

  • \( a = 2 \)
  • \( b = 2 \)

So, \[ d^2 = 2^2 + 2^2 = 4 + 4 = 8 \]

Now, take the square root to find \( d \): \[ d = \sqrt{8} = \sqrt{4 \times 2} = 2 \sqrt{2} \approx 2.828427 \]

Step 3: Round to the nearest hundredth.

So the length of the diagonal, rounded to the nearest hundredth, is: \[ d \approx 2.83 \]

Thus, the length of the diagonal is approximately 2.83.