Respuesta :

Answer : 50 degree

To find angle 1 , we apply outside angle theorem . Refer to the diagram attached below.

 Measurement of arc EF=140 degrees  

Measurement of arc GH = 40

Angle D = angle 1

Theorem says  

[tex]angle D = \frac{arc(EF)-arc(GH)}{2}[/tex]

Now we plug in the values

[tex]angle 1 = \frac{140-40}{2}[/tex]

angle 1 = 50

Measurement of angle 1 = 50 degrees

Ver imagen lisboa