Answer:
45°
135°
Step-by-step explanation:
Let the measure of one angle be x
So, measure of its supplementary angle = 3x
[tex]\implies \: x + 3x = 180 \degree \\ \\ \implies \: 4x = 180 \degree \\ \\\implies \: x = \frac{ 180 \degree}{4} \\ \\\implies \: x = 45 \degree \\ \\ \implies \: 3x = 135 \degree [/tex]