Answer:
measure of arc ABC = 283°
Explanation:
First we have to find y
7y - 7 + 4y + 6 +20y - 11 = 360
31y - 12 = 360
31y = 372
y = 12
Since all the angles are central angles and intercepted arcs of those angles have the same measure,
the measure of arc ABC = 4y + 6 + 20y - 11
= 24y - 5
= 24(12) - 5
= 283