Straight Line

Question 1

Lines with equal gradient are…

Answer 1

Parallel

Question 2

What is the gradient of a horizontal line

Answer 2

m = 0

Question 3

What is the gradient of a vertical line?

Answer 3

m is undefined

Question 4

What is the gradient formula?

Answer 4

Question 5

A line with zero gradient is…

Answer 5

Horizontal (parallel to the x axis)

Question 6

Parallel lines have…

Answer 6

Equal gradient

Question 7

How do you find the equation of a straight line?

Answer 7

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

Question 8

How do you find the mid point of a line?

Answer 8

Question 9

What is the rule for perpendicular lines?

Answer 9

Question 10

What is the distance formula?

Answer 10

Question 11

What is a median of a triangle?

Answer 11

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

Question 12

What is an altitude of a triangle?

Answer 12

Altitude is a line through a vertex, perpendicular to the
opposite side.

Question 13

What is a perpendicular bisector?

Answer 13

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

Question 14

How do you find the equation of a median
through a point of a triangle?

Answer 14

1. Draw a sketch
2. Find the midpoint required
3. Find the gradient from the vertex to the midpoint
4. Use y – b = m( x – a )

Question 15

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

Answer 15

1. Draw a sketch
2. Find the gradient of BC
3. Use m₁ x m₂ = -1 to find
   gradient of the altitude
4. Use y – b = m (x – a)

Question 16

How do you find the equation of a perpendicular bisector?

Answer 16

1. Draw a sketch
2. Find midpoint of AB
3. Find gradient of AB
4. Use m₁ x m₂ = -1 to find gradient of perpendicular bisector CD
5. Use y – b = (m – a )

Question 17

How do you know if a point lies on a line or curve?

Answer 17

Substitute the x and y coordinates of the point into the equation of the line or curve. If the L side = R side, then the point does lie on the line.

Question 18

How do you know 3 lines are concurrent?

Answer 18

For three lines to be concurrent, they must all pass through a single point.
___________________________

Find where 2 lines intersect and sub x and y into 3rd. If Left = Right, then lines are concurrent

Question 19

How do you find the size of the angle between a line and the x-axis?

Answer 19

Question 20

How do you show that the points A, B and C are collinear?

Answer 20

1. Show that m_AB = m_BC
2. State that the two line segments AB and BC have a common point B

Question 21

What does it mean if three points are said to be collinear?

Answer 21

The lie on the same straight line and share a common point

Question 22

What is the equation of this line?

Answer 22

x = -2

Question 23

What is the equation of this line?

Answer 23

y = 4

Question 24

How to you find the gradient of a line in the general form Ax + By + C = 0

Answer 24

Rearrange into y = mx + c

Question 25

How to you find the point where a line cuts the x axis?

Answer 25

Set y = 0

Question 26

How do you find the point where a line cuts the y axis?

Answer 26

Set x = 0

Question 27

How to you find the point where two lines intersect?

Answer 27

Use simultaneous equations