Higher - The gradients of two perpendicular lines will always multiply to make –1. Make sure you are familiar with finding the equation of a line and calculating gradient to understand equations of ...

Now use the information you already have about finding the equation of a line and apply it to the dashed lines shown in these triangles. Remember, to find the equation of a line you need a point ...

Horizontal lines run left to right, parallel to the horizon, with slope 0 and equation y = k. Vertical lines run top to bottom, perpendicular to the horizon, with undefined slope and equation x = k.