Elementary Geometry for College Students (5th Edition)

1. $\angle ABC$ is a right angle 2. $m\angle ABC=90^{\circ}$ 3. $m\angle 1 + m\angle 2=m\angle ABC$ 4. $m\angle 1 + m\angle 2=90^{\circ}$ 5. Ray BD bisects $\angle ABC$ 6. $m\angle 1 = m\angle 2$ 7. $m\angle 1+m\angle 1=90^{\circ}$ 8. $m\angle 1=45^{\circ}$