1. Shape
1.1. Triangle
1.1.1. By sides
1.1.1.1. Scalene triangle no equal sides
1.1.1.2. Isosceles triangle two equal sides
1.1.1.3. Equilateral triangle three equal sides
1.1.2. By angles
1.1.2.1. Acute angled triangle all acute angles
1.1.2.2. Obtuse angled triangle one obtuse angle
1.1.2.3. Right angled triangle one right angle
1.2. Circle
1.3. Square
1.4. Lines
1.4.1. line (AB)
1.4.2. line segment (AB)
1.4.3. concurrent lines
1.4.4. collinear points
1.4.5. perpendicular lines
1.4.6. parallel lines
1.4.7. transversal
1.5. polygons
1.5.1. equilateral triangle
1.5.2. square
1.5.3. pentagon
1.5.4. hexagon
1.5.5. octagon
1.5.6. decagon
1.6. quidrilaterals
1.6.1. parallelogram
1.6.2. rectangle
1.6.3. rhombus
1.6.4. square
1.6.5. trapezium
1.6.6. kite
2. Angle
2.1. Revolution
2.1.1. Angles at a point
2.2. Straight Angle
2.3. Right Angle
2.3.1. Adjacent angles in a right angle
2.3.2. perpendicular lines
2.4. Acute Angle
2.4.1. acute triangle
2.5. Obtuse Angle
2.5.1. obtuse triangle
2.6. Reflex Angle
2.6.1. reflex triangle
2.7. Angle pairs
2.7.1. Complementary angles
2.7.2. Supplementary angles
2.7.3. Adjacent angles
2.7.4. Vertically opposite angles
2.8. Another angles
2.8.1. Corresponding angles
2.8.2. Alternate angles
2.8.3. Co-interior angles(also called allied angles)
2.8.4. Angles of a triangle
2.8.5. Exterior angle of a triangle
2.8.6. Angles of a quadrilateral