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    ANGLE When two rays join together it makes an  angle.  The angle is denoted by degree ( ° ).  TYPES OF ANGLES Acute angle Right angle Obtuse angle Straight angle Reflex angle ACUTE ANGLE The angle is said to be acute which measures less than 90°. ACUTE ANGLE RIGHT ANGLE When the angle measures exactly at 90 ° then it is said to be right angle. RIGHT ANGLE OBTUSE ANGLE The angle is said to be an obtuse when the angle measure is greater than 90 °. OBTUSE ANGLE STRAIGHT ANGLE When an angle is exactly at 180° then it is said to be a straight angle. STRAIGHT ANGLE REFLEX ANGLE The angle is said to be reflex when the measure an angle is greater than 180° and less than 360°. REFLEX ANGLE COMPLEMENTARY ANGLE When two angles are added and if the sum is 90 ° then it is said to be complementary angle. COMPLEMENTARY ANGLE SUPPLEMENTARY ANGLE When two angles are added and if their sum is 180° then it is said to be a supplementary angle.  SUPPLEMENTARY  ANGLE

  SET OPERATIONS We know about set, now we will learn the set of operations. We can visualize relationship between set and set operations using  VENN DIAGRAMS.  COMPLEMENT OF A SET UNION OF TWO SETS INTERSECTION OF TWO SETS DIFFERENCE OF TWO SETS SYMMETRIC DIFFERENCE OF SETS COMPLEMENT OF A SET      The Complement of a set A is the set of all elements of U (the universal set) that are not in A. It is denoted by A′. Venn diagram for complement of a set For example,    If  U = { a, e, i, o, u } and A = { i, u } then A′ = { a, e, o } UNION OF TWO SETS The union of two sets A and B is the set of all elements which are either in A or in B or in both. It is denoted by A∪B and read as A union B.  Venn diagram for union of two sets For example,  If X = { red, yellow, white, blue } and Y = { black, green, pink, orange, brown }  then X ⋃ Y = { red, yellow, white, blue, black, green, pink, orange, brown } INTERSECTION OF TWO SETS The inte...

  TYPES OF SETS 1.Empty Set or Null Set If the set has no element then it is said to be empty set. The empty set is also called as void set or null set. It is denoted by Ø or { }.For example,  The set of all integers between 1 and 2 The set of 30 days in the month of February  2.Singleton Set If the set has only one element then it is said to be singleton set. For example, The set of all even prime numbers The set of all direction of sun rise Cardinal number of a set :   When a set is finite, it is very useful to know how many elements it has. The number of elements in a set is called the Cardinal number of the set. The cardinal number of a set A is denoted by n(A) 3.Finite Set A set with limited number of elements or possible to list is called a finite set. For example, Limited number of students in a class The set of months in a year The set of whole numbers from 0 to 100 4.Infinite Set THE VALUE OF PI  A set which is not limited and impossible to list  i...

  SET LANGUAGE COLLECTION OF FRUITS COLLECTION OF VEHICLES COLLECTION OF FLOWERS   Any collection of objects is called as SET.  Do you think the above objects are related to each other? Yes! The trumpet and xylophone, cooling glass and sun, driller and screw driver, skating cycle and bicycle, football ball and soccer ball, ice cream and cone ice cream. These are the objects related to each other.  COLLECTION OF STATES IN INDIA  COLLECTION OF CLASSICAL DANCE IN INDIA COLLECTION OF SMART STUDENTS IN A CLASS Do you think the above three collections are well defined? The collection of states and classical dance in India are well defined but the collection of smart students in a class are not well defined because it is not specific.          Here “well-defined collection of objects” means that given a specific object it must be possible for us to decide whether the object is an element of the given collection or not. The objects of a set...

Circle In our daily routine, we come across many shapes that are round in shape, such as a wall clock, a wheel, sun moon, earth, coin, bangles, rings, etc. These all shapes are called a circle.  The circle can also be imagined as a single line segment that is bent in a circular shape. Circle Definition A circle is a collection of points in a plane  from a given fixed point. Center The fixed point is called the center of the circle. Radius The fixed distance from the center is called the radius of a circle. Chord:  A line segment joining any two points on the circle is called a chord.  Diameter:  A chord that passes through the center of the circle is called the diameter of a circle. Also diameter is the longest chord and can be expressed as 2r where r is the radius of a circle.  There are infinite numbers of diameter in a circle. Secant:  A chord that intersects the circle in two points is called a secant. Tangent:  A line that touches a circle in...