Solve problems involving gradients of parallel and perpendicular lines (VCMNA338)

LO: To solve problems involving gradient of parallel and perpendicular lines

  • What the gradient of a line
  • How to calculate the gradient of a line
  • What are parallel lines
  • What are perpendicular lines


  • That the gradients of a line can determine whether a pair of lines are parallel or perpendicular.


  • I can solve problems involving the gradient of parallel and perpendicular lines.


A gradient of a line is also called a slope of a line. It basically means how steep is the line.

It can be found using the formula: rise divided by run.

In the case below, it rose 2 while only going across 1, which means this line has a slope (gradient) of 2.

Sometimes the slope (gradient) can go downwards towards the right, which makes the gradient (slope) negative.

Sometimes the slope (gradient) can be very steep (2), and sometimes it can be small (1/2).

A horizontal line has a gradient (slope) of 0 because the rise is always 0. Zero divided by any number is always 0, which makes the gradient of a horizontal line always 0.

Gradients of Parallel and Perpendicular Lines

Parallel Lines have the SAME gradients.

Perpendicular Lines have negative inverse gradients.

Gradient Videos

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