Question

given ( l parallel m parallel n ), find the value of ( x ).

Explanation:

Step1: Identify supplementary angle

The angle supplementary to $126^\circ$ is $180^\circ - 126^\circ = 54^\circ$. This angle is corresponding to $(3x+6)^\circ$ due to parallel lines.

Step2: Set up equation

Since corresponding angles are equal:
$3x + 6 = 54$

Step3: Solve for $x$

Subtract 6 from both sides:
$3x = 54 - 6 = 48$
Divide by 3:
$x = \frac{48}{3} = 16$

Answer:

$x=16$