Angles associated with parallel lines

Two parallel lines are cut by a transversal  the angles formed are alternate angles, corresponding angles co-interior angles and vertically opposite angles.

Objectives
To understand corresponding angles are equal

To understand  alternate angles are equal

Estimated Time
30 minutes

Prerequisites/Instructions, prior preparations, if any
Prior knowledge of point, lines, angles, intersecting lines, vertically opposite angles

Materials/ Resources needed

 * Digital : Computer, geogebra application, projector.
 * Non digital : Worksheet and pencil.
 * Geogebra files : “Parallellines-2.ggb”

Process (How to do the activity)

 * Move the slider to draw a parallel line with the corresponding angles check box unchecked
 * How are the two line with each other
 * What is the line cutting the two line called
 * Bring the slider to initial position : check the corresponding angles check box
 * Move the slider to show corresponding angles formed for the two lines
 * At the point of intersection of the parallel line and transversal : which other angles are equal
 * Is the vertically opposite angle equal to the corresponding angle
 * What are alternate angles are they equal
 * Evaluation at the end of the activity
 * 1) A minimum of how many corresponding angles should be equal for any two lines to be parallel.
 * 2) How many pairs of corresponding angles are formed when a transversal intersects two parallel lines?
 * 3) How many pairs of alternate angles are formed when  a transversal intersects two parallel lines?