258 Index
circle, 105
norm
vector, 190
null duo-angle, 169
null vector, 191
null-angle, 30
open half-plane, 26
opposite
vertex and side in triangle, 31
half-lines, 25
opposite sides
convex quadrilateral, 32
opposite vertices
convex quadrilateral, 32
order
natural, 22
reciprocal, 23
orientation
frame reference, 160
point triple, 160
origin, 81
orthocentre, 204
Pappus’ theorem, 201
parallel, 54
parallelogram, 63
parameter
point on line, 92
parametric equations
line, 92
Pascal’s theorem, 177
perimeter
convex quadrilateral, 32
triangle, 31
perpendicular
drop, 57
perpendicular erected, 44
perpendicular lines, 44
plane, 21
point, 21
initial, 25
point pairs
equipollent, 185
point triple
orientation, 160
points
areal coordinates, 193
polar coordinates, 133
polygon
convex, 76
polygonal region
area, 78
position vector, 192
power, 118
principle
ASA, 52
SAS, 50
SSS, 53
product
sensed, 116
product by a scalar
vector, 188
projection, 57
Ptolemy’s theorem, 167
Pythagoras’ theorem, 69quadrants, 81
quadrilateral
convex, 32
cyclic, 114radian measure
angle, 247
radical axis, 118
radius
circle, 103
range
harmonic, 71
ratio
complex, 148
sensed, 116
reciprocal order, 23
rectangle, 63
reference
axes, 81
frame, 81
reflex angle