Questions: Find the value of (x). [ x= ]

Find the value of \(x\).

Find the third angle of the triangle.

Let the third angle be \(y\). The sum of the angles in a triangle is \(180^\circ\). Therefore, \(60^\circ + 78^\circ + y = 180^\circ\). \(138^\circ + y = 180^\circ\) \(y = 180^\circ - 138^\circ\) \(y = 42^\circ\)

The third angle of the triangle is \(42^\circ\).

Find the value of \(x\).

\(x\) and \(y\) are supplementary angles, so their sum is \(180^\circ\). \(x + y = 180^\circ\) \(x + 42^\circ = 180^\circ\) \(x = 180^\circ - 42^\circ\) \(x = 138^\circ\)

\(\boxed{x = 138^\circ}\)

\(\boxed{x = 138^\circ}\)