In the diagram above, quadrilateral ABCD is a rhombus. If the m ∠DAB

= 124 °
find the measurements below.

(3 points)
m∠ABC=

°

m∠AEB=

°

m∠ADE

1 answer

In a rhombus, opposite angles are equal, and adjacent angles are supplementary. This means that:

  1. For the angles:

    • Since \( m\angle DAB = 124° \), we have: \[ m\angle ABC = m\angle DAB = 124° \]
    • Thus, \( m\angle ABC = 124° \).
  2. Calculating the other angles:

    • The angles adjacent to \( m\angle DAB \) and \( m\angle ABC \) are supplementary: \[ m\angle ABC + m\angle BCD = 180° \]
    • Therefore: \[ m\angle BCD = 180° - 124° = 56° \]
    • And since opposite angles in a rhombus are equal: \[ m\angle ABC = m\angle DAB = 124° \quad \text{and} \quad m\angle BCD = m\angle DAB = 56° \]
  3. Finding angle \( m\angle AEB \):

    • The points A, B, D, and E give a diagonal split through vertex angles. The angle \( m\angle AEB \) sits within the triangle ABE formed by the diagonals intersecting at point E.
    • In a rhombus, the diagonals bisect the angles: \[ m\angle AEB = \frac{m\angle DAB}{2} = \frac{124°}{2} = 62° \]
  4. Finding angle \( m\angle ADE \):

    • Using the same property of bisected angles, angle \( m\angle ADE \) is half of angle DAB: \[ m\angle ADE = \frac{m\angle DAB}{2} = \frac{124°}{2} = 62° \]

Thus, we can summarize the answers as follows:

  • \( m\angle ABC = 56° \)
  • \( m\angle AEB = 62° \)
  • \( m\angle ADE = 62° \)