Given the rectangle ABCD as shown, find AC if AO=9x−1 and DO=6x+17 . (1 point) AC=

1 answer

To find the length of diagonal AC in rectangle ABCD, we use the properties of rectangles and the information given.

In rectangle ABCD, points A, B, C, and D are the corners, and point O is the intersection point of the diagonals (which is also the midpoint of each diagonal). In any rectangle, the diagonals bisect each other.

Given:

  • AO = \(9x - 1\)
  • DO = \(6x + 17\)

Since O is the midpoint of both diagonals, AO = OC and DO = OB. In a rectangle, the lengths of these segments are equal, hence: \[ AO = DO \] So, we set the equations equal to each other: \[ 9x - 1 = 6x + 17 \]

Now, we solve for \(x\):

  1. Subtract \(6x\) from both sides: \[ 9x - 6x - 1 = 17 \] \[ 3x - 1 = 17 \]

  2. Add \(1\) to both sides: \[ 3x = 18 \]

  3. Divide both sides by \(3\): \[ x = 6 \]

Now that we have \(x\), we substitute it back to find the lengths of AO and DO:

Calculate AO: \[ AO = 9x - 1 = 9(6) - 1 = 54 - 1 = 53 \]

Since AO = OC and DO = OB, both segments AO and DO equal 53 units.

Now we need to calculate the length of diagonal AC. In a rectangle: \[ AC = 2 \times AO = 2 \times 53 = 106 \]

Therefore, the length of diagonal AC is: \[ \boxed{106} \]