Answer:
[tex]m\ arc\ ABC=270^o[/tex]
Step-by-step explanation:
we know that
[tex]m\ arc\ AC+m\ arc\ ABC=360^o[/tex] ----> by complete circle
we have
[tex]m\ arc\ AC=90^o[/tex] ----> by central angle
so
substitute in the equation above
[tex]90^o+m\ arc\ ABC=360^o[/tex]
[tex]m\ arc\ ABC=360^o-90^o=270^o[/tex]
