When twice an angle is added to 45∘ we get the supplement of this angle. Find the angle.
45o
Two angles whose sum is 180∘ are known as supplementary angles.
Let the unknown angle be x∘
Supplement of 45∘ is 135∘ .
Twice the unknown angle is 2x∘.
So, 2x∘+45∘=135∘
2x∘=90∘
x=45∘