# 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

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

## Multimedia resources

## Website interactives/ links/ simulations/ Geogebra Applets

## Process (How to do the activity)

Play with the following Geogebra applet

## Developmental Questions (What discussion questions)

- Move the Blue points observe the changes
- record the Slopes of two lines
- Compare the values

## Evaluation (Questions for assessment of the child)

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