Download STRAIGHT LINE Distance Formula The distance between the points

STRAIGHT LINE
Distance Formula
The distance between the points (x1,y1) and (x2,y2) is found using the formula:
√(
)
(
)
Mid-point Formula
We can find the mid-point of the line AB using the formula:
(
)
Gradient
We can find the gradient between 2 points, (x1,y1) and (x2,y2), using the formula:
Angles & Gradients: The anti-clockwise angle between the positive direction of the
x-axis and a line are connected by the formula:
Parallel lines have the same gradient:
The gradients of perpendicular lines are connected using the formula:
Equation Of A Straight Line
Horizontal Lines
A horizontal line has equation y = a
where a is the point that the line crosses the y-axis.
Vertical Lines
A vertical line has equation x = b
where b is the point that the line crosses the x-axis.
Diagonal Lines
The equation of a diagonal line can be found using
the formulae:
where m is the gradient and c is the y-intercept.
(
)
where m is the gradient and (a,b) is a point on the line.
Altitudes
An altitude is a line drawn, in a triangle,
from a vertex and it is perpendicular to
the opposite side.
Medians
A median is a line drawn, in a triangle,
from a vertex to the midpoint of the
opposite side.
Perpendicular Bisectors
B
A perpendicular bisector is a
line that bisects (cuts in half)
another line and it is at right
angles to the line.
A
Mid-point of AB
Straight Line Practice
http://www.bbc.co.uk/bitesize/higher/maths/geometry/the_straight_line/revision/1/
Revise the rule and try the TESTBITE.
http://www.supermathsworld.com/ Ask your teacher for the login details.
Select EXPERT from the bottom menu. Select COORDINATE GEOMETRY from the menu. Try DISTANCE, MID-POINT,
GRADIENT, PERPENDICULAR & EQUATION OF A LINE.
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pps&ei=RMWaU-f-LcSDOImUgIAP&usg=AFQjCNGLXLokDceQR6OQRikRB0AaCs9a4A&bvm=bv.68911936,d.ZGU
A powerpoint presentation on the straight line.