2 &
w
c)) In the figure alongside, if x + y + z = 180°,
prove that w = y + z.
Answers
A.67
Linear pair of angles:
If Non common arms of two adjacent angles form a line, then these angles are called linear pair of angles.
Axiom- 1
If a ray stands on a line, then the sum of two adjacent angles so formed is 180°i.e, the sum of the linear pair is 180°.
Axiom-2
If the sum of two adjacent angles is 180° then the two non common arms of the angles form a line.
The two axioms given above together are called the linear pair axioms.
Solution:
Given,
x + y = w + z
To Prove,
AOB is a line or
x + y = 180° (linear pair.)
Proof:
A.T.Q
x + y + w + z = 360° (Angles around a point.)
(x + y) + (w + z) = 360°
(x + y) + (x + y) = 360°
(Given x + y = w + z)
2(x + y) = 360°
(x + y) = 180°
Hence, x + y makes a linear pair.
Therefore, AOB is a straight line.
Hope this will help you....