Tiana draws quadrilateral ABCD as shown, with the measures of ZA, ZB, ZC, and D represented. For what values of m and n is Tiana guaranteed that ABCD is a parallelogram?

(1 point)
If m=? and n=? then Tiana is guaranteed that ABCD is a
parallelogram.

1 answer

In order for quadrilateral ABCD to be a parallelogram, certain angle relationships must hold true. Specifically, a quadrilateral is a parallelogram if:

  1. Opposite angles are equal, i.e., \( \angle A = \angle C \) and \( \angle B = \angle D \), or
  2. The sum of the measures of consecutive angles is supplementary, i.e., \( \angle A + \angle B = 180^\circ \) and \( \angle C + \angle D = 180^\circ \).

If Tiana has defined \( \angle A = m \), \( \angle B = n \), \( \angle C \), and \( \angle D \) in terms of \( m \) and \( n \), we can establish conditions based on the above definitions.

  1. If opposite angles are equal:

    • For opposite angles:
      • \( \angle A = m \) and \( \angle C = m \) suggests \( \angle C\) must also equal \( m \).
      • And \( \angle B = n\) and \( \angle D = n\) suggests \( \angle D\) must also equal \( n \).
  2. If the sum of consecutive angles is supplementary:

    • \( m + n = 180^\circ \) guarantees that the two angles \( A + B\) are supplementary, implying that the figure must be a parallelogram.

Without more specific information about the angles in quadrilateral ABCD, we cannot determine exact numeric values for \( m \) and \( n \). Instead, we can provide conditions:

  • For the case of equal opposite angles: \( m + n + m + n = 360^\circ \) thereby establishing conditions for A, B, C, D proportional to \( m\) and \( n \).

  • For the case of supplementary angles: \( m + n = 180^\circ \).

If you can provide specific angle measures for \( m \) and \( n \) or more context to the angles in question, I can confirm the values. However, in a general case, if \( m + n = 180\), then ABCD will definitely be a parallelogram.

Thus, in summary:

  • If \( m = 60^\circ \) then \( n = 120^\circ \) (or similarly for any other pairs summing to 180 degrees).

Hence,

  • To guarantee that ABCD is a parallelogram, Tiana should establish that if \( m + n = 180^\circ \).