- 3x + 2x + 5 + 5x + 15 = 180 [angles on a line add to 180 degrees]
- 10x + 20 = 180 [combine like terms]
- 10x = 160 [subtract 20 from both sides]
- x = 16 [divide both sides by 10]
Arc AB measures 3(16) = 48 degrees.
Arc BC measures 2(16) + 5 = 41 degrees.