Distance/ Length
√(X2-X1)^2 + (y2-y1)^2
Midpoint
(x1+x2/2; y1+y2/2)
gradient
m = y2-y1/x2-x2
|| lines
m1-m2=0 m1=m2
perpindicular lines
m1×m2 =-1ORreciprocal
collinear
mAB = mCD
diagonal bisected
midpoints =
trapezium
1 pair of parallel sides
parallelogram
Diagonals bisect each other
rhombus
parallelogramdiagonals perpendicular
rectangle
parallelogram with 1 right angles (90°)
square
rhombus & 1 90° angle ORrectangle & diagonals perpendicular
kite
1 diagonal bisected at 90°