Answer:
see below
Explanation:
by looking at the given image...
the shape ABCD is a parallelogram.
Required:
is to prove ∡A and ∡B are supplementary
and ∡C and ∡D are supplementary.
so, m∠A + m∠B = 180°
and m∠C + m∠D = 180°
the Statement
1. ABCD is a parallelogram
the reason is..
It is Given!
the Statement
2.m∠A=m∠C and m∠B=m∠D
the reason is..
Definition of parallelogram.
the Statement
3.m∠A+m∠B+m∠C+m∠D=360°
the reason is..
Definition of quadrilateral
the Statement
4. m∠A+m∠B+m∠A+m∠B=360°
the reason is..
By substitution
⇒ 2( m∠A + m∠B ) = 360°
⇒ m∠A + m∠B = 180°
it is also similar m∠C + m∠D = 180°
the Statement
5.∠A and ∠C are supplementary
the reason is..
by the definition of Supplementary ∠ B and ∠D are supplementary
Hope it helps!