INTRODUCTION

INTRODUCTION:

• Length:  The distance between the end points of a line segment.
• Straight Angle: The angle whose measure is 180˚.
• Right Angle: The angle whose measures is 90˚.
• Reflex Angle: The angle whose measure is more than a straight angle (180˚) but less than one complete angle (360˚).
• Revolution: The one complete turn made by two straight angles.
• Acute Angle: An angle smaller than right angle is called acute angle.
• Obtuse Angle: An angle larger than a right angle, but less than a straight angle.
• Perpendicular: When two lines intersect and the angle between them is a right angle.
• Scalene Triangle: A triangle having three unequal sides.
• Isosceles Triangle: A triangle having 2 equal sides.
• Equivalent Triangle: A triangle having 3 equal sides
                                                                                                                                                                        Classification of Triangles based on their angles :

  Nature of angles is the triangle	Name
  Each angle is acute	Acute angled triangle
  One angle is right angle	Right angled triangle
  One angle is obtuse	Obtuse angled triangle

  Classification of Quadrilaterals based on their properties: 

  Properties	Name of the Quadrilateral
  Two pairs of parallel sides	Parallelogram
  Parallelogram with 4 right angles	Rectangle
  Parallelogram with 4 sides equal length	Rhombus
  A rhombus with 4 right angle	Square