Answer:
45
Step-by-step explanation:
We know that the shape is a triangle, and the first angle is 90 degrees.
since 1 and 2 are equal, and we know that the sum of the angles in a triangle is 180, we have:
180-90 = 90/2 = 45
(are you sure this is an 8th grade question? Because I'm 10 years old....)
