Slope of parallel and perpendicular lines

From Karnataka Open Educational Resources

Activity - Name of Activity

Parallel lines have the same slope and slope of perpendicular lines are the negative reciprocals of each other

Estimated Time

1 Hour

Materials/ Resources needed

Geogebra applet

Prerequisites/Instructions, if any

  1. Students should know that every line is a representation of an equation /relation between variables
  2. Graphing an equation/producing equation by visualising graph
  3. Students should know what is Slope?
  4. Similarity of two triangles

Multimedia resources

Website interactives/ links/ simulations/ Geogebra Applets

Process (How to do the activity)

Play with the following Geogebra applet

[From this geogebra applet we can visualise that slope of two parallel lines are same and slope of two perpendicular lise are negetive resiprocals of each other]

Developmental Questions (What discussion questions)

  1. Move the Blue points observe the changes
  2. record the Slopes of two lines
  3. Compare the values

Evaluation (Questions for assessment of the child)

Can we prove that the given triangle is Right angled triangle?

Question Corner

Activity Keywords

[Back to Co-ordinate geometry Page Link]