Topics
Linear equations in two variables
 Linear Equation in Two Variables
 Simultaneous Linear Equations
 Elimination Method
 Substitution Method
 Cross  Multiplication Method
 Graphical Method of Solution of a Pair of Linear Equations
 Determinant of Order Two
 Cramer’s Rule
 Equations Reducible to a Pair of Linear Equations in Two Variables
 Simple Situational Problems
 Pair of Linear Equations in Two Variables
Quadratic Equations
 Quadratic Equations
 Roots of a Quadratic Equation
 Solutions of Quadratic Equations by Factorization
 Solutions of Quadratic Equations by Completing the Square
 Formula for Solving a Quadratic Equation
 Nature of Roots of a Quadratic Equation
 The Relation Between Roots of the Quadratic Equation and Coefficients
 To Obtain a Quadratic Equation Having Given Roots
 Application of Quadratic Equation
Arithmetic Progression
 Introduction to Sequence
 Terms in a sequence
 Arithmetic Progression
 General Term of an Arithmetic Progression
 Sum of First n Terms of an A.P.
 Arithmetic Progressions Examples and Solutions
 Geometric Progression
 General Term of an Geomatric Progression
 Sum of the First 'N' Terms of an Geometric Progression
 Geometric Mean
 Arithmetic Mean  Raw Data
 Concept of Ratio
Financial Planning
Probability
 Probability  A Theoretical Approach
 Basic Ideas of Probability
 Random Experiments
 Outcome
 Equally Likely Outcomes
 Sample Space
 Event and Its Types
 Probability of an Event
 Type of Event  Elementry
 Type of Event  Complementry
 Type of Event  Exclusive
 Type of Event  Exhaustive
 Concept Or Properties of Probability
 Addition Theorem
Statistics
 Tabulation of Data
 Inclusive and Exclusive Type of Tables
 Ogives (Cumulative Frequency Graphs)
 Applications of Ogives in Determination of Median
 Relation Between Measures of Central Tendency
 Introduction to Normal Distribution
 Properties of Normal Distribution
 Concepts of Statistics
 Mean of Grouped Data
 Method of Finding Mean for Grouped Data: Direct Method
 Method of Finding Mean for Grouped Data: Deviation Or Assumed Mean Method
 Method of Finding Mean for Grouped Data: the Step Deviation Method
 Median of Grouped Data
 Mode of Grouped Data
 Concept of Pictograph
 Presentation of Data
 Graphical Representation of Data as Histograms
 Frequency Polygon
 Concept of Pie Graph (Or a Circlegraph)
 Interpretation of Pie Diagram
 Drawing a Pie Graph
definition
Pie graph(Or a Circlegraph): A piegraph is used to compare parts of a whole. A circle graph shows the relationship between a whole and its part. Here, the whole circle is divided into sectors. The size of each sector is proportional to the activity or information it represents.
notes
Pie graph(Or a Circlegraph):

A piegraph is used to compare parts of a whole.

Data can also be presented using a circle graph or pie chart. A circle graph shows the relationship between a whole and its part. Here, the whole circle is divided into sectors. The size of each sector is proportional to the activity or information it represents.
The following pie graph shows the percentage of viewers watching different types of TV channels.
Drawing pie charts:
1) The favourite flavours of icecreams for students of a school are given in percentages as follows.
Flavours 
Percentage of students

Chocolate 
50% 
Vanilla 
25% 
Other flavours 
25% 
Let us represent this data in a pie chart.
The total angle at the centre of a circle is 360°. The central angle of the sectors will be a fraction of 360°. We make a table to find the central angle of the sectors.
Flavours 
Students in percent preferring the flavours 
In fractions 
Fraction of 360° 
Chocolate  50%  `50/100 = 1/2`  `1/2 "of" 360° =180°` 
Vanilla  25%  `25/100 = 1/4`  `1/4 "of" 360° = 90°` 
Other flavours  25%  `25/100 = 1/4`  `1/4 "of" 360° = 90°` 
 Draw a circle with any convenient radius. Mark its centre (O) and a radius (OA).

The angle of the sector for chocolate is 180°. Use the protractor to draw ∠AOB = 180°.
 Continue marking the remaining sectors.
Example
ordinary bread  320 
fruit bread  80 
cakes and pastries  160 
biscuits  120 
others  40 
Total

720 
Item  Sales (In Rs.)  In Fraction  Central Angle 
Ordinary Bread  320  `320/720 = 4/9`  `4/9xx360° = 160°` 
Fruit Bread  80  `80/720 = 1/9`  `1/9xx360° = 40°` 
Cakes and pastries  160  `160/720 = 2/9`  `2/9xx360° = 80°` 
Biscuits  120  `120/720 = 1/6`  `1/6xx360° = 60°` 
Others  40  `40/720 = 1/18`  `1/18xx360° = 20°` 
Video Tutorials
Shaalaa.com  Drawing Pie Charts
Related QuestionsVIEW ALL [30]
The following table shows the daily supply of electricity to different places in a town. To show the information by a pie diagram, measures of central angles of sectors are to be decided.
Complete the following activity to find the measure :
Places 
Supply of electricity 
Measure of central angle 
Roads  4  `4/30 xx 360 = 48^circ` 
Factories  12  `square/square xx 360 = 144^circ` 
shops  6  `6/30 xx 360 = square` 
Houses  8  `square/square xx 360 = square` 
Total ⇒  30  `square` 
The following table shows the percentages of demands for different fruits registered with a fruit vendor. Show the information by a pie diagram.
Fruits  Mango  Sweet lime  Apples  Cheeku  Oranges 
Percentages of demand  30  15  25  20  10 