### Home > INT2 > Chapter 7 > Lesson 7.1.4 > Problem7-49

7-49.

Carolina compares her proof to Penn’s work in problem 7-39. Like him, she wants to prove that if $\overline{AD} // \overline{EH}$ and $\overline{BF} // \overline{CG}$, then $a = d$. Unfortunately, her statements are in a different order. Examine her proof below and help her decide if her statements are in a logical sequence to prove that $a = d$.

 Statements Reasons $1$. $\overline{AD} // \overline{EH}$ Given $2$. $a = b$ If lines are parallel, alternate interior angles are equal. $3$. $a = c$ Substitution $4$. $\overline{BF} // \overline{CG}$ Given $5$. $b = c$ If lines are parallel, corresponding angles are equal. $6$. $c = d$ Vertical angles are equal. $7$. $a = d$ Substitution

Be sure to start with the "Given" statements. Then, if lines are parallel, which pairs of angles will be congruent?