- Books Name
- CBSE Class 6 Mathematics Book
- Publication
- Param Publication
- Course
- CBSE Class 6
- Subject
- Mathmatics
Kinds of angle
Angles are classified according to their degree measure.
(i) Acute Angle : An angle smaller than a right angle is called an acute angle.
(ii) Right Angle : An angle which measures 90º is called a right angle. In Fig. ABC is a right angle.
(iii) Obtuse Angle : If an angle is larger than a right angle, but less than a straight angle, it is called an obtuse angle.
(iv) Straight Angle : An angle which measures 180° is called a straight angle in figure. ∠ABC is a straight angle.
(v) Reflex Angle : An angle which measures greater than 180° and less than 360° is called a reflex angle. ∠AOC is a reflex angle.
(vi) Complete Angle : An angle which measures 360° is called a complete angle. ∠AOB is complete angle.
Perpendicular lines
When two lines intersect and the angle between them is a right angle, then the lines are said to be perpendicular. If a line AB is perpendicular to CD, we write AB ⊥CD.
Perpendicular bisector
A line perpendicular to the given line segment as well as bisects it, is called perpendicular bisector. Line LM is perpendicular bisector of line segment AB.