What is the value of x, when a scalene triangle's measurements are x, 2x, and 54 ?

The value of x is 42
For given scalene triangle, the measure of all three angles will be different.
Since, the sum of angles of a triangle is equal to 180°.
[tex]x+2x+54 = 180\\3x+54 = 180\\3x=180-54\\3x=126\\x=\frac{126}{3} \\x=42[/tex]
[tex]2x = 42\times 2 = 84[/tex]
Therefore, the angles of the scalene triangle are 42°, 84° and 54°