# Straight Line Flashcards

Lines with equal gradient are…

Parallel

What is the gradient of a horizontal line

m = 0

What is the gradient of a vertical line?

m is undefined

What is the gradient formula?

A line with zero gradient is…

Horizontal (parallel to the x axis)

Parallel lines have…

Equal gradient

How do you find the equation of a straight line?

- Find the
**gradient** - Need to know a point on the line
**(a, b)** - Sub into
**y - b = m( x - a )**

How do you find the mid point of a line?

What is the rule for perpendicular lines?

What is the distance formula?

What is a median of a triangle?

Median is a line drawn from one vertex to the midpoint of the opposite side

What is an altitude of a triangle?

Altitude is a line through a vertex, perpendicular to the

opposite side.

What is a perpendicular bisector?

A line which bisects (cuts in half) a given line at right-angles

How do you find the equation of a median

through a point of a triangle?

- Draw a sketch
- Find the
**midpoint**required - Find the
**gradient**from the vertex to the midpoint - Use
**y – b = m( x – a )**

How do you find the equation of an altitude of a triangle through side BC?

- Draw a sketch
- Find the
**gradient**of BC - Use
**m**to find_{1 }x m_{2}= -1

gradient of the altitude - Use
**y – b = m (x – a)**