Topics
Basic Concepts in Geometry
Parallel Line
 Parallel Lines
 Checking Parallel Lines
 Pairs of Lines  Transversal of Parallel Lines
 Properties of Parallel Lines
 Interior Angle Theorem
 Corresponding Angle Theorem
 Alternate Angles Theorems
 Use of properties of parallel lines
 Test for Parallel Lines
 Interior Angles Test
 Alternate Angles Test
 Corresponding Angles Test
 Corollary of Parallel Lines
Triangles
 Concept of Triangles  Sides, Angles, Vertices, Interior and Exterior of Triangle
 Remote Interior Angles of a Triangle Theorem
 Exterior Angle of a Triangle and Its Property
 Congruence of Triangles
 Isosceles Triangles Theorem
 Converse of Isosceles Triangle Theorem
 Corollary of a Triangle
 Property of 30° 60° 90° Triangle Theorem
 Property of 45° 45° 90° Triangle Theorem
 Median of a Triangle
 Property of Median Drawn on the Hypotenuse of Right Triangle
 Perpendicular Bisector Theorem
 Angle Bisector Theorem
 Properties of inequalities of sides and angles of a triangle
 Similar Triangles
 Similarity of Triangles
Constructions of Triangles
 Perpendicular Bisector Theorem
 Construction of Triangles
 To Construct a Triangle When Its Base, an Angle Adjacent to the Base, and the Sum of the Lengths of Remaining Sides is Given.
 To Construct a Triangle When Its Base, Angle Adjacent to the Base and Difference Between the Remaining Sides is Given.
 To Construct a Triangle, If Its Perimeter, Base and the Angles Which Include the Base Are Given.
Quadrilaterals
 Concept of Quadrilaterals  Sides, Adjacent Sides, Opposite Sides, Angle, Adjacent Angles and Opposite Angles
 Properties of a Parallelogram
 Properties of Rhombus
 Properties of a Square
 Properties of Rectangle
 Properties of Trapezium
 Property: The Opposite Sides of a Parallelogram Are of Equal Length.
 Property: The Opposite Angles of a Parallelogram Are of Equal Measure.
 Property: The diagonals of a parallelogram bisect each other. (at the point of their intersection)
 Property: The adjacent angles in a parallelogram are supplementary.
 Tests for Parallelogram
 Theorem : If Each Pair of Opposite Sides of a Quadrilateral is Equal, Then It is a Parallelogram.
 Theorem: If in a Quadrilateral, Each Pair of Opposite Angles is Equal, Then It is a Parallelogram.
 Theorem : If the Diagonals of a Quadrilateral Bisect Each Other, Then It is a Parallelogram
 Theorem: If One Pair of Opposite Sides of a Quadrilateral Are Equal and Parallel, It is a Parallelogram.
 Property: The Diagonals of a Rectangle Are of Equal Length.
 Property: Diagonals of a Square Are Congruent.
 Property: The diagonals of a square are perpendicular bisectors of each other.
 Property: Diagonals of a Square Bisect Its Opposite Angles.
 Property: The diagonals of a rhombus are perpendicular bisectors of one another.
 Property: Diagonals of a Rhombus Bisect Its Opposite Angles.
 Properties of Isosceles Trapezium
 Theorem of Midpoints of Two Sides of a Triangle
 Converse of Midpoint Theorem
Circle
 Concept of Circle  Centre, Radius, Diameter, Arc, Sector, Chord, Segment, Semicircle, Circumference, Interior and Exterior, Concentric Circles
 Properties of Chord
 Theorem: a Perpendicular Drawn from the Centre of a Circle on Its Chord Bisects the Chord.
 Theorem : The Segment Joining the Centre of a Circle and the Midpoint of Its Chord is Perpendicular to the Chord.
 Relation Between Congruent Chords of a Circle and Their Distances from the Centre
 Properties of Congruent Chords
 Theorem: Equal chords of a circle are equidistant from the centre.
 Theorem : The Chords of a Circle Which Are Equidistant from the Centre Are Equal.
 Incircle of a Triangle
 Construction of the Incircle of a Triangle.
 Circumcentre of a Triangle
 Construction of the Circumcircle of a Triangle
Coordinate Geometry
Trigonometry
Surface area and volume
definition
Plane: Plane is a flat surface on which a straight line joining any two points on it would wholly lie.
notes
Plane:

In mathematics, a flat surface is called a plane.

Each flat surface is a part of an infinite surface.
 Plane is a flat surface on which a straight line joining any two points on it would wholly lie.

Even though we draw a suitably small figure of the plane, it actually extends infinitely on all sides. Arrows are drawn to show that the plane extends infinitely in all directions. However, these arrows are often omitted for the sake of convenience.

The 2dimensional shapes or objects in geometry are flat plane figures that have two dimensions – length and width. Twodimensional or 2D shapes do not have any thickness and can be measured in only two faces.
A plane figure can be made of straight lines, curved lines, or both straight and curved lines. The circle, the square, the rectangle, the quadrilateral and the triangle are examples of plane figures.