Answer:
42°
Step-by-step explanation:
- Measures of the two interior angles of the triangle are b and 90°
- Measure of the remaining interior angle of the triangle will be 48° by the property of first corresponding angles and then vertical angles.
[tex]\therefore b + 48 \degree + 90 \degree = 180 \degree \\ b + 138 \degree = 180 \degree\\ b = 180 \degree - 138 \degree \\ b = 42 \degree [/tex]