Answer:
∠ X = 102°.
Step-by-step explanation:
See the figure attached.
This is a quadrilateral with angles 72°, (18x - 3)°, (18x - 6)° and 81°.
Now, the sum of all the four angles of the given quadrilateral will be 360°.
So, 72 + (18x - 3) + (18x - 6) + 81 = 360
⇒ 36x + 144 = 360
⇒ 36x = 216
⇒ x = 6
Therefore, ∠ X = 18x - 6 = 18(6) - 8 = 102° (Answer)
