### Enclosing Squares

Can you find sets of sloping lines that enclose a square?

### Graphical Triangle

Weekly Problem 35 - 2007
What is the area of the triangle formed by these three lines?

### Reflecting Lines

Investigate what happens to the equations of different lines when you reflect them in one of the axes. Try to predict what will happen. Explain your findings.

# Parallel Lines

##### Stage: 3 Challenge Level:

Alter the positions of the line by moving the points.
How does the position of the line affect the equation of the line?

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Now explore what happens when you have two lines.
Position the lines so that they are parallel to each other.
Try various arrangements.

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What can you say about the equations of parallel lines?

You may want to take a look at Perpendicular Lines after this.