ANGLES

• Obtuse angle


  An angle that is bigger or greater than a right angle
• Straight angle


  An angle formed by two rays pointing in exactly opposite directions, which is just a straight line
• Complementary angles


  Two angles that combine to form a right angle
• Supplementary angles


  Two angles that combine to form a straight angle
• Angle


  A measurement of rotation
• Degree


  A small amount of rotation used to measure angles
• Angles can't be measured with a ruler or in units like centimeters
• The word 'degree' is used for different things like temperature and angles</b>
• Measuring an angle


  1. Place two rays pointing in the same direction

  2. Rotate one ray counter-clockwise

  3. The angle between the rays is measured in degrees
• Angle of 0 degrees


  • Rays point in the same direction
• Angle of 90 degrees


  • Rays are perpendicular, forming a right angle
• Angle of 180 degrees


  • Rays point in opposite directions, forming a straight angle
• Angle regions


  • Acute angles (0-90 degrees)
  • Obtuse angles (90-180 degrees)
• Angle of 45 degrees


  • Half of a right angle
• Angle of 270 degrees


  • Forms a right angle pointing down
• Angle of 360 degrees


  • Completes a full circle
• Protractor


  A tool used to measure angles
• Complementary angles


  Combine to form a right angle (90 degrees)
• Supplementary angles


  Combine to form a straight angle (180 degrees)
• Solving for unknown angle in a complementary or supplementary pair

  1. Find total angle (90 or 180 degrees)

  2. Subtract known angle

  3. Remaining angle is the unknown
• Angle


  Formed when two lines meet at a point (the vertex)
• Angle


  • Measured in degrees or rotations
• Types of angles

  • Acute
  • Right
  • Obtuse
  • Reflex
  • Straight
• Acute angle

  Angle less than 90 degrees
• Right angle


  Angle exactly 90 degrees
• Obtuse angle


  Angle greater than 90 degrees but less than 180 degrees
• Straight angle


  Angle exactly 180 degrees
• Reflex angle

  Angle greater than 180 degrees but less than 360 degrees
• Angles

  • Angle A (acute)
  • Angle B (right)
  • Angle C (obtuse)
  • Angle D (right)
  • Angle E (reflex)
• Angles are puzzles, so it's suggested to watch a playlist on finding internal and external angles
• The video includes a quick quiz to test understanding of the different angle types