LIVE Mathematics on the web

Index

About Points

If you like the taste of dynamic geometry that you experience here, then contact AAMT about purchasing Cabri-Geometry II.

Points are the building blocks of dynamic geometry. These must be created before you can construct lines, circles, polygons or any other elements. There are many point options available in the Geometry Applet, and these are explained here.

Element class point

Construction method Construction data Description
free integers x, y a freely dragable point in the screen plane with initial coordinates (x,y,0)
midpoint points A, B the midpoint of a line AB
intersection points A, B, C, D
[plane E]		 the intersection of two lines AB and CD in the plane E
points B, C
plane A		 the intersection of the plane A and the line BC
first points A, B the first end A of the line AB
last points A, B the last end B of the line AB
center circle A the center of the circle A
sphere A the center of the sphere A
lineSlider points A, B
integers x, y,[z]		 a point that slides along a line AB with initial coordinates (x,y,z)
circleSlider circle A
integers x, y,[z]		 a point that slides along a circle A with given initial coordinates (x,y,z)
circumcenter points A, B, C
[plane D]		 the center of a circle ABC passing through 3 points A, B, and C in the plane D
vertex polygon A
integer i		 a vertex Ai of the polygon A1A2...An with index i
foot points A, B, C the foot of a perpendicular drawn from A to a line BC
point A
plane B		 the foot of a perpendicular drawn from A to a plane B
cutoff points A, B, C, D the point E on a line AB so that AE = CD
extend points A, B, C, D the point E on a line AB so that BE = CD
parallelogram points A, B, C the 4th vertex D of a parallelogram ABCD given 3 vertices A, B, and C
similar points A, B, D, E, F
[planes C, G]		 the point H so that triangle ABH in plane C is similar to triangle DEF in plane G
perpendicular points A, B,
[plane C]		 the point D so that AD is equal and perpendicular to AB in plane C
points A, B, D, E
[plane C]		 the point F so that AF is perpendicular to AB in plane C and equals DE
points A, C, D
plane B		 the point E on the line perpendicular to plane B passing through A so that the distance from E to B equals CD
proportion 8 points A, B, C, D, E, F, G, H the point I on GH so that AB:CD = EF:GI
invert point A
circle B		 the image of a point A inverted in the circle B
meanProportional 6 points A, B, C, D, E, F the point G on EF so that AB:CD = CD:EG
planeSlider plane A
integers x, y, z		 a point that slides on the plane A with initial coordinates (x,y,z)
sphereSlider sphere A
integers x, y, z		 a point that slides on the sphere A with initial coordinates (x,y,z)
angleBisector points A, B, C
[plane D]		 The point at the intersection of the angle bisector of angle BAC and the line BC in plane D
angleDivider points A, B, C
[plane D]
integer n		 The point E on the line BC so that angle BAE is the nth part of the angle BAC in plane D
fixed integers x, y, z the fixed point with coordinates (x, y, z)
lineSegmentSlider points A, B
integers x, y,[z]		 a point that slides along within the line segment AB with initial coordinates (x,y,z)

Index

David E. Joyce
Department of Mathematics and Computer Science
Clark University
Worcester, MA 01610

Email: djoyce@clarku.edu
My nonJava Homepage and my Java homepage