Respuesta :

Use the note that Linear pairs have sum 180°

  • TD is a straight line

[tex]\\ \rm\rightarrowtail m\overset{\frown}{CD}+122=180[/tex]

[tex]\\ \rm\rightarrowtail m\overset{\frown}{CD}=180-122=58°[/tex]

Now

  • DB arc be x

  • A whole angle is 360° or 2π

[tex]\\ \rm\rightarrowtail x+122+58+90=360[/tex]

[tex]\\ \rm\rightarrowtail x+270=360[/tex]

[tex]\\ \rm\rightarrowtail m\overset{\frown}{DB}=90°[/tex]

Answer:

90

Step-by-step explanation: