MATHEMATICS

  Circle   A circle is easy to make: Draw a curve that is "radius" away from a central point. And so: All points are the same distance from the center. You Can Draw It Yourself Put a pin in a board, put a loop of string around it, and insert a pencil into the loop. Keep the string stretched and draw the circle!   The  Radius  is the distance from the center outwards. The  Diameter  goes straight across the circle, through the center. The  Circumference  is the distance once around the circle. And here is the really cool thing: When we divide the circumference by the diameter we get 3.141592654... which is the number  π  ( Pi ) So when the diameter is 1, the circumference is 3.141592654...   We can say: Circumference =  π  × Diameter Example: You walk around a circle which has a diameter of 100m, how far have you walked? Distance walked = Circumference =  π  × 100m =  314m  (to the nearest m) Also n...

  Properties of Quadrilaterals Let us understand in a better way with the help of an example: It has four sides: AB, BC, CD, and DA It has four vertices: Points A, B, C, and D It has four angles: ∠ABC, ∠BCD, ∠CDA, and ∠DAB ∠A and ∠B are adjacent angles ∠A and ∠C are the opposite angles AB and CD are the opposite sides AB and BC are the adjacent sides A quadrilateral is a 4-sided plane figure. Below are some important properties of quadrilaterals : Every quadrilateral has 4 vertices, 4 angles, and 4 sides The total of its interior angles = 360 degrees Square Properties All the sides of the square are of equal measure The sides are parallel to each other All the interior angles of a square are at 90 degrees (i.e., right angle) The diagonals of a square perpendicular bisect each other Rectangle Properties The opposite sides of a rectangle are of equal length The opposite sides are parallel to each other All the interior angles of a rectangle are 90 degrees. The diagonals of a rectangl...

  A   quadrilateral   is a closed shape and a type of polygon that has four sides, four vertices and four angles. It is formed by joining four non-collinear points. The   sum of interior angles   of quadrilaterals is always equal to 360 degrees. The word quadrilateral is derived from the Latin words ‘ Quadra ’ which means four and ‘ Latus ’ means ‘sides’. It is not necessary that all the four sides of a quadrilateral are equal in length. Hence, we can have different types of quadrilaterals based on sides and angles. Let us more interesting facts about quadrilaterals in this article.  A quadrilateral is a plane figure that has four sides or edges, and also has four corners or vertices. The angles are present at the four vertices or corners of the quadrilateral. If ABCD is a quadrilateral then angles at the vertices are ∠A, ∠B, ∠C and ∠D. The sides of a quadrilateral are AB, BC, CD and DA.  If we join the opposite vertices of the quadrilateral, we get th...

  What are Angles When two rays combine with a common endpoint and the angle is formed. The two components of an angle are “sides” and “vertex”. The side can be categorized into terminal sides and initial sides (or vertical sides) as shown in the image below. Representation of an Angle These two rays can combine in multiple fashions to form the different types of angles in mathematics. Let us begin by studying these different types of angles in geometry. Parts of Angle Vertex – Point where the arms meet. Arms – Two straight line segments form a vertex. Angle – If a ray is rotated about its endpoint, the measure of its rotation is called angle between its initial and final position. Classification of Angles Angles can be classified into two main types: Based on Magnitude Based on Rotation Angle Types Based on Magnitude Six Types of Angles In Maths, there are mainly 5 types of angles based on their direction. These five angle types are the most common ones used in geometry. These are...

  Irrational Numbers An  Irrational Number  is a real number that  cannot  be written as a simple fraction:   1.5  is rational, but  π  is irrational Irrational means  not Rational  (no ratio) Let's look at what makes a number rational or irrational ... Rational Numbers A  Rational  Number  can  be written as a  Ratio  of two integers (ie a simple fraction). Example:  1.5  is rational, because it can be written as the ratio  3/2 Example:  7  is rational, because it can be written as the ratio  7/1 Example  0.333...  (3 repeating) is also rational, because it can be written as the ratio  1/3   Irrational Numbers But some numbers  cannot  be written as a ratio of two integers ... ...they are called  Irrational Numbers . Example:  π   (Pi)  is a famous irrational number. π  = 3.1415926535897932384626433832795... ...

  Pi ( π )   Draw a circle with a  diameter  (all the way across the circle) of  1 Then the  circumference  (all the way around the circle) is  3.14159265...  a number known as  Pi   Pi  (pronounced like "pie") is often written using the greek symbol  π The definition of  π  is: The  Circumference divided by the  Diameter of a Circle. The circumference divided by the diameter of a circle is always  π , no matter how large or small the circle is!   To help you remember what  π  is ... just draw this diagram. Finding Pi Yourself Draw a circle, or use something circular like a plate. Measure around the edge (the  circumference ): I got  82 cm Measure across the circle (the  diameter ): I got  26 cm Divide: 82 cm / 26 cm = 3.1538... That is pretty close to  π . Maybe if I measured more accurately? Using Pi We can use  π  to find a Circumference when we ...