Straight lines in every day life, the example of a moving car.
The general equation of a straight line has the from y=mx+c. You can plot the line by generating two points.
A point can be on, above, or below a line; and this can be investigated algebraically.
The intercept coordinates of a straight line with the axes can be estimated visually or found exactly using algebra.
The gradient of a line is the rise over run. The gradient can be found of a line passing through two points.
The equations of vertical and horizontal lines are simple since the m-value have special values. The gradient of a horizontal line is zero, whereas the gradient of a vertical line is infinity.
Parallel lines never intersect and have the same gradient.
Perpendicular lines intersect to define a 90 degree intersection angle.
The intersection point of two lines can be estimated by plotting the lines, and the exact coordinate can be found algebraically.