LINES AND ANGLES
We have studied that a minimum of two points are required to draw a line and also studied that some axioms and,with the help of these axioms,we proved some other statement .now we will study the properties of the angles formed when two lines intersect each other, and also the properties of the angles formed when a line intersect two or more parallel lines at distinct points.
LINES AND ANGLES
KAILASH SABESAN JUSTIN POLOCKAL
SAURABH KOLTARKAR SUMIT SHINDE
angle: an angle is the union of two non-collinear rays with a common initial point
The two rays forming an angles are called the “arms” of the angles and the common initial point is called the “vertex” of the angle.
The angle formed by the rays AB and AC as shown in fig 1.a is denoted by the BAC or CAB.
INTERIOR OF AN ANGLE
The interior of an angle BAC is the set of all point in its plane,which lie on the same side of AB as C and also on the same side of AC as B.
EXTERIOR OF AN ANGLES
The exterior of an angle BAC is the set of all points in its plane,which do not lie on the angle or in its interior.
Two angles are said to be congruent if a trace copy of one can be superposed on the other to cover it completely and exactly.
1.2 MEASURE OF AN ANGLE
Angle measure axiom:every angle has a measure. the unit of angle measure is a standard angle,called a “degree”.
If the measure of angle BAC is x degrees, we denote it by BAC=x
CONGRUENT ANGLE MEASURE AXIOM
Two congruent angles have the same measure and conversely two angles of equal measure are congruent.
Thus BAC= DEF ( m BAC =m DEF.
1.3 TYPES OF ANGLES
Right angle: an angle whose measure is 90 is called a right angle.
Acute angle: an angle whose measure is less than 90 is...