One of the corners of the quadrilateral is 112 degrees. Find the sum of the other angles.

The sum theorem of the angles of a quadrilateral states: in a non-self-intersecting quadrilateral, the sum of all interior angles is 360 °.
Let’s denote the four corners of the quadrangle as ∠1, ∠2, ∠3 and ∠4, then the sum of these angles is 360 °:
∠1 + ∠2 + ∠3 + ∠4 = 360 °.
By condition, ∠1 = 112 °. Substitute the angle value into equality:
112 ° + ∠2 + ∠3 + ∠4 = 360 °.
Let’s leave the unknown angles on the left side of the equality:
∠2 + ∠3 + ∠4 = 360 ° – 112 °.
In this way:
∠2 + ∠3 + ∠4 = 248 °.
Answer: 248 °.