What’s the angle for y?

y=42

Step-by-step explanation:

The sum of the angles of a triangle add to 180

y+ 48+ 90 = 180

The third angle is 90 because supplementary angles add to 180 and the other side is a 90 degree angle, which makes that angle equal to 90

y+ 48+ 90 = 180

Combine like terms

y +138 = 180

Subtract 138 from each side

y+138-138 = 180-138

y =42