# Straight Line Flashcards

1
Q

Parallel lines…

A

2
Q

For perpendicular lines the following is true..

Example M qp and M qo

A

M qp = b M qo = - a
— And —
a b

• M qp X M qo = b -a
— X — = -1
a b

3
Q

A

M = y2 - y1
——–
x2 - x1

4
Q

C = ?

A

Y intercept ( 0,c )

5
Q

M = ?

A

Tan 0

6
Q

Midpoint

A

Mid =
x1 + x2 y1 + y2
——- , ——-
2 2

7
Q

How to find Median?

A
• Midpoint:
```     x1 + x2      y1 + y2
-------  ,   -------
2               2```
```   y2 - y1
--------
x2 - x1```
• Substitute into y - b= m( x - a )
8
Q

How do you find the perpendicular bisector ?

A
• Midpoint:
```      x1 + x2      y1 + y2
-------  ,   -------
2               2```
```   y2 - y1
--------
x2 - x1```

M qp X M qo = b -a
— X — = -1
a b

• substitute into y - b = m ( x - a)
9
Q

Altitude of a triangle

A
```   y2 - y1
--------
x2 - x1```

M qp X M qo = b -a
— X — = -1
a b
- substitute into y - b = m ( x - a )

10
Q

Median of a triangle

A
• midpoint:
```      x1 + x2      y1 + y2
-------  ,   -------
2               2```
```   y2 - y1
--------
x2 - x1```
• substitute into y - b = m ( x - a )
11
Q

Distance between 2 points

A

D = (x2 - x1)^2 + ( y2 - y1) ^2

12
Q

Form for finding line equation

A

y - b = m (x - a )

( a, b) = point on the line

13
Q

Concurrent lines

A
• Simultaneous equations
• Find y
Sub in y into equation
• Sub in again to find x
• To find the lines pass through ( a, b ) so they are concurrent
14
Q

Intersecting lines

A
1. Median
• midpoint