Answer:
1) c ║ d by consecutive interior angles theorem
2) m∠3 + m∠6 = 180° by transitive property
3) ∠2 ≅ ∠5 by definition of congruency
4) t ║ v
Corresponding angle theorem
5) ∠14 and ∠11 are supplementary
Definition of supplementary angles
6) ∠8 and ∠9 are supplementary
Consecutive interior angles theorem
Step-by-step explanation:
1) Statement
Reason
m∠4 + m∠7 = 180°
Given
m∠4 ≅ m∠6
Vertically opposite angles
m∠4 = m∠6
Definition of congruency
m∠6 + m∠7 = 180°
Transitive property
m∠6 and m∠7 are supplementary
Definition of supplementary angles
∴ c ║ d
Consecutive interior angles theorem
2) Statement
Reason
m∠3 = m∠8
Given
m∠8 + m∠6 = 180°
Sum of angles on a straight line
∴ m∠3 + m∠6 = 180°
Transitive property
3) Statement
Reason
p ║ q
Given
∠1 ≅ ∠5
Given
∠1 = ∠5
Definition of congruency
∠2 ≅ ∠1
Alternate interior angles theorem
∠2 = ∠1
Definition of congruency
∠2 = ∠5
Transitive property
∠2 ≅ ∠5
Definition of congruency.
4) Statement
Reason
∠1 ≅ ∠5
Given
∠3 ≅ ∠4
Given
∠1 = ∠5
Definition of congruency
∠3 = ∠4
Definition of congruency
∠5 ≅ ∠4
Vertically opposite angles
∠5 = ∠4
Definition of congruency
∠5 = ∠3
Transitive property
∠1 = ∠3
Transitive property
∠1 ≅ ∠3
Definition of congruency.
t ║ v
Corresponding angle theorem
5) Statement
Reason
∠5 ≅ ∠16
Given
∠2 ≅ ∠4
Given
∠5 = ∠16
Definition of congruency
∠2 = ∠4
Definition of congruency
EF ║ GH
Corresponding angle theorem
∠14 ≅ ∠16
Corresponding angles
∠14 = ∠16
Definition of congruency
∠5 = ∠14
Transitive property
∠5 + ∠11 = 180°
Sum of angles on a straight line
∠14 + ∠11 = 180°
Transitive property
∠14 and ∠11 are supplementary
Definition of supplementary angles
6) Statement
Reason
l ║ m
Given
∠4 ≅ ∠7
Given
∠4 = ∠7
Definition of congruency
∠2 ≅ ∠7
Alternate angles
∠2 = ∠7
Definition of congruency
∠2 = ∠4
Transitive property
∠2 ≅ ∠4
Definition of congruency
∠2 and ∠4 are corresponding angles
Definition
DA ║ EB
Corresponding angle theorem
∠8 and ∠9 are consecutive interior angles
Definition
∠8 and ∠9 are supplementary
Consecutive interior angles theorem.