Find the supplement of each of the following angles:
${138}^{\circ }$

Finding the supplementary angle:

1. When the sum of the two angles is equal to ${180}^{\circ }$, the two angles are said to be supplementary angles.
2. The supplement angle can be found by subtracting the given angle from ${180}^{\circ }$.

Let, the supplement angle of ${138}^{\circ }$ be x.
${138}^o+x={180}^o$
$x={42}^o$
Hence, the supplement angle of ${138}^{\circ }$is ${42}^{\circ }$.