Answer:
∠ Y = 45°, ∠ X = 135°
Step-by-step explanation:
Since the 2 angles are supplementary, then
X + Y = 180 ← substitute X = 3Y
3Y + Y = 180, that is
4Y = 180 ( divide both sides by 4 )
Y = 45
and
X + Y = 180, so
X + 45 = 180 ( subtract 45 from both sides )
X = 135
Thus
∠ X = 135° and ∠ Y = 45°
