#### Answer

1. $\angle1$ and $\angle2$ are right angles. $\overline{CA}$≅$\overline{DA}$ 1. Given
2. $\overline{AB}≅\overline{AB}$ 2.Reflexive Property
3. △ABC≅△ABD 3. SAS

#### Work Step by Step

1. Fill out the information in the first statement that was given to you, then for your proof, write given.
2. Notice, that the two triangles share a similar line between both of them which is segment $\overline{AB}$ and use the reflexive property.
3. List that the triangles you need to prove are congruent then label the order of sides and angles, then you will get in the proof collum, SAS.
No work needed when doing a proof other than marking the triangle. Although, for extra insurance, copy down the triangle and label the parts that are congruent and show your understanding of how these two triangles are congruent.