Topics
Number Systems
Number Systems
Algebra
Polynomials
Linear Equations in Two Variables
Algebraic Expressions
Algebraic Identities
Coordinate Geometry
Geometry
Introduction to Euclid’S Geometry
Lines and Angles
Triangles
Quadrilaterals
 Concept of Quadrilaterals  Sides, Adjacent Sides, Opposite Sides, Angle, Adjacent Angles and Opposite Angles
 Angle Sum Property of a Quadrilateral
 Types of Quadrilaterals
 Another Condition for a Quadrilateral to Be a Parallelogram
 Theorem of Midpoints of Two Sides of a Triangle
 Property: The Opposite Sides of a Parallelogram Are of Equal Length.
 Theorem: A Diagonal of a Parallelogram Divides It into Two Congruent Triangles.
 Theorem : If Each Pair of Opposite Sides of a Quadrilateral is Equal, Then It is a Parallelogram.
 Property: The Opposite Angles of a Parallelogram Are of Equal Measure.
 Theorem: If in a Quadrilateral, Each Pair of Opposite Angles is Equal, Then It is a Parallelogram.
 Property: The diagonals of a parallelogram bisect each other. (at the point of their intersection)
 Theorem : If the Diagonals of a Quadrilateral Bisect Each Other, Then It is a Parallelogram
Area
Circles
 Concept of Circle  Centre, Radius, Diameter, Arc, Sector, Chord, Segment, Semicircle, Circumference, Interior and Exterior, Concentric Circles
 Angle Subtended by a Chord at a Point
 Perpendicular from the Centre to a Chord
 Circles Passing Through One, Two, Three Points
 Equal Chords and Their Distances from the Centre
 Angle Subtended by an Arc of a Circle
 Cyclic Quadrilateral
Constructions
Mensuration
Areas  Heron’S Formula
Surface Areas and Volumes
Statistics and Probability
Statistics
Probability
definition
Triangle: A triangle is a closed figure made by joining three noncollinear points by line segments. A triangle is a threesided polygon.
notes
Triangles:

A triangle is a threesided polygon. In fact, it is the polygon with the least number of sides.
 A triangle is a closed figure made by joining three noncollinear points by line segments.

It has three sides, three angles, and three vertices.
 The vertices, sides and angles of a triangle are called the parts of the triangle.
 We write ∆ABC instead of writing "Triangle ABC".
 ‘Length of line segment AB’ is written as l(AB).
 The three sides of the triangle are `bar"AB", bar"BC", and bar"CA"`.
The three angles are ∠BAC, ∠BCA, and ∠ABC.
The points A, B, and C are called the vertices of the triangle.

Being a polygon, a triangle has an exterior and an interior.
 P is in the interior of the triangle, R is in the exterior and Q on the triangle.
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