**1.1 Angles and Lines II**

**Identifying Parallel, Transversals, Corresponding Angles, Alternate Angles and Interior Angles**

**(A)**

**Parallel lines**

Parallel lines are lines with the same direction. They remain the same distance apart and never meet.

**(B)**

**Transversal lines**

(C)

(C)

**Alternate angles**

**(D)**

**Corresponding angles**

**(E)**

**Interior angles**

*PT3 Smart TIP*Alternate angles are easily identified by tracing out the pattern

**“Z”**as shown.Corresponding angles are easily identified by the pattern

**“F”**as shown.

Interior angles are easily identified by the pattern

**“C”**as shown.

**Example 1:**

Construct a line parallel to

*PQ*and passing through*W*.*a*= 40

^{o}and

*b*= 50

^{o}← (Alternate angles)

*y*=

*a*+

*b*

= 40

^{o}+ 50^{o } =

**90**^{o }**Example 2:**

In Diagram below,

$$\begin{array}{l}\angle WSQ={180}^{o}-{150}^{o}\\ \text{}={30}^{o}\leftarrow \overline{)\text{Supplementary angle}}\\ \angle XTU=\angle WSQ+\angle x\leftarrow \overline{)\text{Corresponding angle}}\\ \text{}{75}^{o}={30}^{o}+\angle x\\ \text{}\angle x={75}^{o}-{30}^{o}\\ \text{}\angle x={45}^{o}\\ \text{}x=45\end{array}$$
*PSQ*and*STU*are straight lines. Find the value of*x*.