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 note that the Diameter is twice the Radius: Diameter = 2 × Radius And so this is

  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 rectangle bi

  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 the diagonals. In the below figure A