When two parallel lines are crossed by another line (called a transversal), they create special angles. Recognizing these angles is important for learning about geometry. Let’s break it down in simple terms!

What Are Alternate Angles?

• Alternate Interior Angles: These are the angles found between the two parallel lines. They are on opposite sides of the transversal.

• Alternate Exterior Angles: These angles are located outside the parallel lines, also on opposite sides of the transversal.

How to Spot Them:

1. Draw a Picture: Start by drawing two parallel lines. Let’s call them line $l$ and line $m$. Then, draw a transversal line $t$ that crosses both.

   

2. Label the Angles: When the transversal crosses the lines, label the angles. You can call the angles on line $l$ as $1$, $2$, $3$, and $4$. Name the angles on line $m$ as $5$, $6$, $7$, and $8$.

3. Finding Alternate Angles:

   • Example of Alternate Interior Angles: Angles $3$ and $6$ are alternate interior angles.
   • Example of Alternate Exterior Angles: Angles $1$ and $8$ are alternate exterior angles.

Important Facts:

• When the lines are parallel, alternate angles are always equal. So, if $\angle 3 = \angle 6$, that tells us the lines are indeed parallel.

Remember, finding these angles will help you solve different geometry problems and build your understanding of how angles relate to each other!