Answer: 53°
Explanation:
3x - 4 + 3x + 6 + 4x - 12 = 180
10x - 10 = 180
Add 10 to both sides
10x = 190
Divide both sides by 10
x = 19
3x - 4
3 (19) - 4 = 57 - 4
= 53
3x + 6
3 (19) + 6 = 57 + 6
= 63
4x - 12
4 (19) - 12 = 76 - 12
= 64
The smallest angle is 53°