32 This is a regular pentagon.
which iwe triangles within
the figure are congruent by
the SAS rule? Write all the
catresponding parts
B
Answers
Answer:
• The sum of adjacent angles on a straight line is 180◦.
(If L is a line then a + b = 180◦.)
Abbreviation: ∠s on a line. b a
L
• The sum of adjacent angles around a point is 360◦.
(a + b + c + d = 360◦.)
Abbreviation: ∠s at a pt.
b
c
d
a
• Vertically opposite angles are equal.
(At the intersection of two straight lines, a = c and b = d).
Abbreviation: vert. ∠s.
b
c
d
a
• When a transversal intersects parallel lines, corresponding angles are equal.
(If AB∥CD then a = b.)
Abbreviation: corr. ∠s, AB∥CD.
• Conversely, if a = b then AB∥CD.
Abbreviation: corr. ∠s converse.
b
a
A B
C D
• When a transversal intersects parallel lines, alternate interior angles are equal.
(If AB∥CD then a = c.)
Abbreviation: alt. ∠s, AB∥CD.
• Conversely, if a = c then AB∥CD.
Abbreviation: alt. ∠s converse.
a
c
A B
C D
• When a transversal intersects parallel lines, interior angles on the same side of the transversal
are supplementary.
(If AB∥CD then a + d = 180◦.)
Abbreviation: int. ∠s, AB∥CD.
• Conversely, if a + d = 180 then AB∥CD.
Abbreviation: int. ∠s converse.
a d
A B
C D
• The angle sum of any triangle is 180◦. (*)
(a + b + c = 180◦.)
Abbreviation: ∠ sum of ∆.
b
c
a
• Each exterior angle of a triangle is the sum of the opposite interior angles. (*)
(e = a + b).
Abbreviation: ext. ∠ of ∆.
Step-by-step explanation: