COORDINATE
GEOMETRY
Calculating Distance
Who is closest to the pot of gold?
Three pirates are on a
quest to find the pot of
gold, situated at the origin
{0,0}.
The pirates are located at
the following points:
Calico Jack – { -4 , 5 }
Black Beard – { -7 , -1 }
Long John Silver – { 6 , 2 }
The measurements are in
kilometres.

Who is the closest?
Who is closest to the pot of gold?
Three pirates are on a
quest to find the pot of
gold, situated at the origin
{0,0}.
The pirates are located at
the following points:
Calico Jack – { -4 , 5 }
Black Beard – { -7 , -1 }
Long John Silver – { 6 , 2 }
Who is the closest?
Who is closest to the pot of gold?
Use the formula (based on
Pythagoras’ theorem)

C – { -4 , 5 }

O–{0,0}

Distance = (x2 - x1 )2 + (y2 - y1 )2
Who is closest to the pot of gold?
C – { -4 , 5 }

O–{0,0}

Distance = (x2 - x1 )2 + (y2 - y1 )2
Distance = (0 - -4)2 + (0 - 5)2
= (16 + 25)

= 41

Distance for Calico Jack to gold is 6.4km (to 1 dp) or 41 km
Who is closest to the pot of gold?
Calico Jack – { -4 , 5 }

C = 41 km
Black Beard – { -7 , -1 }

B = (0 - -7)2 + (0 - -1)2
B = (49 +1)

Distance = (x2 - x1 ) + (y2 - y1 )
2

2

B = 50 km
Long John Silver – { 6 , 2 }

L = (0 - 6)2 + (0 - 2)2
Long John Silver is the closest to the Pot
of gold at
40 km

L = (36 + 4)

L = 40 km
Dragon’s Revenge
The computer game “Dragon’s Revenge” uses coordinates
to place objects in the game.
Dracon the dragon, who is near death, can only fire his
fireball a distance of 6 metres. Three attackers are in view.
He cannot afford to waste any fireballs. Dracon is situated
at the point (5,4)
The soldiers are placed at
A (8,7)
B (2,-1)
C (9,0)
Can Dracon kill all the soldiers? Show all your working.
Dragon’s Revenge
• Distance AD

A
D

C
B

AD = (8 - 5)2 + (7 - 4)2
AD = (9 + 9
AD = 18
• Distance CD

CD = (2 - 5)2 + (-1- 4)2
CD = 9 + 25

CD = 34
• Distance BD

BD = (9 - 5)2 + (0 - 4)2
BD = 16 +16

BD = 32

Coordinate Geometry - Distance

  • 1.
  • 2.
    Who is closestto the pot of gold? Three pirates are on a quest to find the pot of gold, situated at the origin {0,0}. The pirates are located at the following points: Calico Jack – { -4 , 5 } Black Beard – { -7 , -1 } Long John Silver – { 6 , 2 } The measurements are in kilometres. Who is the closest?
  • 3.
    Who is closestto the pot of gold? Three pirates are on a quest to find the pot of gold, situated at the origin {0,0}. The pirates are located at the following points: Calico Jack – { -4 , 5 } Black Beard – { -7 , -1 } Long John Silver – { 6 , 2 } Who is the closest?
  • 4.
    Who is closestto the pot of gold? Use the formula (based on Pythagoras’ theorem) C – { -4 , 5 } O–{0,0} Distance = (x2 - x1 )2 + (y2 - y1 )2
  • 5.
    Who is closestto the pot of gold? C – { -4 , 5 } O–{0,0} Distance = (x2 - x1 )2 + (y2 - y1 )2 Distance = (0 - -4)2 + (0 - 5)2 = (16 + 25) = 41 Distance for Calico Jack to gold is 6.4km (to 1 dp) or 41 km
  • 6.
    Who is closestto the pot of gold? Calico Jack – { -4 , 5 } C = 41 km Black Beard – { -7 , -1 } B = (0 - -7)2 + (0 - -1)2 B = (49 +1) Distance = (x2 - x1 ) + (y2 - y1 ) 2 2 B = 50 km Long John Silver – { 6 , 2 } L = (0 - 6)2 + (0 - 2)2 Long John Silver is the closest to the Pot of gold at 40 km L = (36 + 4) L = 40 km
  • 7.
    Dragon’s Revenge The computergame “Dragon’s Revenge” uses coordinates to place objects in the game. Dracon the dragon, who is near death, can only fire his fireball a distance of 6 metres. Three attackers are in view. He cannot afford to waste any fireballs. Dracon is situated at the point (5,4) The soldiers are placed at A (8,7) B (2,-1) C (9,0) Can Dracon kill all the soldiers? Show all your working.
  • 8.
    Dragon’s Revenge • DistanceAD A D C B AD = (8 - 5)2 + (7 - 4)2 AD = (9 + 9 AD = 18 • Distance CD CD = (2 - 5)2 + (-1- 4)2 CD = 9 + 25 CD = 34 • Distance BD BD = (9 - 5)2 + (0 - 4)2 BD = 16 +16 BD = 32