Answer:
x = 18
Step-by-step explanation:
- Line E B C Needs To Equal 180°
3x + 5 + 3x + 4 + 3x + 9 = 180
- Simplify Both Sides Of The Equation
(3x + 3x + 3x) + (5 + 4 + 9) = 180( Combine Like Terms)
9x + 18 = 180
9x + 18 = 180
- Subtract 18 From Both Sides
9x + 18 − 18 = 180 − 18
9x = 162
Divide Both Sides By 9
9x / 9 = 162 / 9
x = 18