Parallel lines and Perpendicular lines

Objectives
To enable students to-
 * 1) understand the concept of parallel lines and perpendicular	lines;
 * 2) identify differences between parallel lines and non parallel	lines;
 * 3) understand about when two lines can be parallel (constant	perpendicular distance)
 * 4) to measure the perpendicular distance between two lines.
 * 5) to provide hands-on experience through Geogebra application.

Estimated Time
90 minutes

Prerequisites/Instructions, prior preparations, if any
Prior understanding of lines and angles, right angle as 90 degree, use of protractor to measure/draw an angle.

Materials/ Resources needed

 * Digital : Computer, Geogebra	application, projector.
 * Non-digital : Geometrical tools, pencil and worksheet.

Process (How to do the activity)
Teachers work: Students work:
 * Show examples of pictures with parallel and non-parallel	lines.
 * Help students to identify their differences.
 * Ask students on how they can conclude two line/segments are	parallel and record the same.
 * Introduce about the concept of perpendicular lines
 * Help students understand that perpendicular line is the	shortest distance between a pair of lines.
 * Demonstrate using Geogebra how to plot parallel lines and	check if perpendicular distance remains fixed between them.
 * Ask students to give more examples of parallel lines in real	life situations and their importance.
 * Identify the difference between parallel and non-parallel	lines.
 * Identify the parallel lines in their surroundings and measure	the distance between them at various regions.
 * Plot parallel lines using Geogebra and try to measure	perpendicular distance between them.
 * Plot perpendicular line using Geogebra and understand it as	the shortest distance between two lines.
 * Analyse the importance of parallel lines in real life	situations.

Developmental questions of the activity

 * 1) When can we say two lines to be parallel and non-parallel?
 * 2) What is the shortest distance between a pair of parallel lines?
 * 3) What is the angle measurement of line drawn as shortest distance between the pair of parallel lines?
 * 4) What is the length of the perpendicular line drawn at various positions between two parallel lines?
 * 5) Where do you see perpendicular lines in our surroundings?
 * 6) Where do you see parallel lines in real life situations? What is the importance of lines been parallel in them?

Application questions:

 * Why are the rods of a window parallel?
 * Why are the electric cables laid parallel to each?
 * Can buildings have slant or perpendicular pillars? Why?
 * Why are  Football stadiums rectangles?
 * Why are  doors and windows usually rectangular?
 * Why are some crops grown in fields parallel(example-cabbage)?