Answer:
x = 20°
Step-by-step explanation:
here's your solution
=>. we know that, sum of two opposite interior angle is equal to one exterior
=> (3x)° + (3x -20)° = (7x - 40)°
=> 6x - 20° = 7x - 40
=> - x = - 20
=> x = 20
hope it helps
20°
C.20 is the correct answer.
