Question: What are the values of $x$, $y$, and $z$? Use theorems to justify each answer.
74°
$x°$
66°
$y°$
$z°$
By the Choose answer 1 Angles Theorem and the Triangle Choose answer 2 Theorem, $x = $ Choose answer 3.
1. **State the problem:** We are given a diagram with two vertical parallel lines and two slanted lines crossing them, forming angles labeled $74^\circ$, $x^\circ$, $66^\circ$, $y^\circ$, and $z^\circ$. We need to find the values of $x$, $y$, and $z$ using angle theorems.
2. **Identify the theorems:**
- Since the vertical lines are parallel, corresponding angles and alternate interior angles are equal.
- The sum of angles in a triangle is $180^\circ$.
3. **Find $x$:**
- The angle $74^\circ$ and angle $x$ are alternate interior angles formed by the transversal crossing the parallel lines.
- Therefore, by the Alternate Interior Angles Theorem, $x = 74^\circ$.
4. **Find $y$:**
- At the upper-right intersection, angles $66^\circ$, $y^\circ$, and $x^\circ$ form a triangle.
- Sum of angles in a triangle is $180^\circ$:
$$66 + y + x = 180$$
- Substitute $x = 74$:
$$66 + y + 74 = 180$$
- Simplify:
$$140 + y = 180$$
- Solve for $y$:
$$y = 180 - 140 = 40$$
5. **Find $z$:**
- The angle $z$ and angle $y$ are corresponding angles formed by the transversal crossing the parallel lines.
- By the Corresponding Angles Theorem, $z = y = 40^\circ$.
**Final answers:**
$$x = 74^\circ, \quad y = 40^\circ, \quad z = 40^\circ$$