Answer: First option.
Step-by-step explanation:
For this exercise it is important to observe the picture given in the exercise and analize the information provided.
You can observe in the picture that the measure of the angle ADC can be obtained my adding the measures of the angles ADB and BDC. Therefore, knowing this, you can write the following equation:
[tex]m\angle ADC=m\angle ADB+m\angle BDC[/tex]
You can identify in the picture that:
[tex]m\angle ADB=89\°\\\\m\angle BDC=42\°[/tex]
Therefore, you can substitute those values into the equation and then evaluate in order to find the measure of the angle ADC.
You get that this is:
[tex]m\angle ADC=89\°+42\°\\\\m\angle ADC=131\°[/tex]
