Simple list of web pages I have created for mathematical topics.
Sum of 2 sides from a point to ends of line greater than from included point.
Triangles with 2 sides & included angle equal (Euclid 1.4)
Triangle greater side subtends greater angle (Euclid 1-18)
Triangle sum of angles = 2 rt. angles (Euclid 1.32)
Parallelogram diagonal creates equal triangles (Euclid 1. 34 - Part)
Parallelograms on same base between parallels are equal (Euclid 1.35)
Triangles on the same base are equal (Similar to Euclid Book 1 Prop 35)
Triangle: Isosceles triangle has equal angles
Triangle: Line joining mid-points of triangle is parallel to other side
Triangle: Line drawn through 2 sides of triangle parallel to 3rd divide sides proportionally
Triangle: Line from right angle to hypotenuse mid-point creates 2 isos. triangle
Right Angle Triangle with hypotenuse and one side equal are identical
Triangle: Pythagoras - Right Angle Triangle (Euclid 1.47)
Parallel lines cut by transversal, interior alternate angles are equal
Parallel lines cut by transversal, corresponding angles are equal
Quantities in proportion are also in proportion by composition
Chord subtends angle twice as big at centre than at circumference of circle