Answer:
y + x + 90°=180°( sum of triangle=180°/Angeles of a triangle are supplementary)
y + x=180°-90°
there for x=y (Given by the theorem) OR two opposite angles of a triangle are equally
x+x= 90°/y+y=90° Note: Since y=x then sub y by x or y instead of the same equition (y=x)
x+x/y+y=90°
2x=90°
x=45°
or
x+y=90°
45+y=90°
y=90°-45°
y=45°
