Answer:
45°
Step-by-step explanation:
let the angle be x, then
The supplement of x is 180 - x and the complement of x is 90 - x, thus
180 - x = 3(90 - x) ← equation of model, that is
180 - x = 270 - 3x ( add 3x to both sides )
2x + 180 = 270 ( subtract 180 from both sides )
2x = 90 ( divide both sides by 2 )
x = 45
Thus required angle is 45°
