for what value of a does m∠1=90
126
138
150
180

Answer:
[tex]x=150[/tex]
Step-by-step explanation:
we know that
sum of all angles around inscribed a point is always 270
so,
first angle is 42
second angle is x-12
third angle is <1
so, we get
<1 +42 +x-12=270
we can plug <1=90
[tex]90+42+x-12=270[/tex]
[tex]90+42+x-12=270[/tex]
[tex]x+120=270[/tex]
[tex]x=150[/tex]