Respuesta :

choixongdong
3x - 1.5 = 1/2(3x+9)
2(3x - 1.5) = 3x + 9
6x - 3 = 3x + 9
3x = 12
  x = 4

arc AC = 3(4) + 9 = 12 + 9 = 21

answer
21

Answer:

AC = 21⁰

Step-by-step explanation:

arc AC has central angle 3x+9 n its inscribed angle <ABC is 3x-1.5

central angle = 2 * inscribed angle

3x+9 = 2 * (3x-1.5)

3x+9 = 6x -3

3x = 12

x = 4

so arc AC = (3*4 + 9) = 21⁰