Name:__________________________
Date:______ Period:_____
Parallel Lines & Transversals
Ms. Anderle
Parallel Lines and Transversals
Parallel lines are __________________ lines that __________________.
Parallel lines also have _____________________.
A line that intersects two or more coplanar lines at two different points is called a
_______________. When a transversal "cuts" two or more parallel lines, special
relationships develop.
The diagram below shows the relationships between the angles.
1
4
2
3
5 6
8
7
Interior Angles line inside the two parallel lines. Alternate interior angles are congruent.
Pairs of alternate interior angles: ________________________________________
Exterior Angles lie outside the two parallel lines. Alternate exterior angles are congruent.
Pairs of alternate exterior angles: _______________________________________
Corresponding Angles are angles that are in the same position. If you would lie the two
lines on top of each other, the angles would be in exactly the same spot.
Pairs of corresponding angles: ____________________________________________
Supplementary Angles add up to 180˚. These angles are next to each other.
Pairs of supplementary angles:_____________________________________________
The "BS" Rule: We can use this rule to help us figure out which angles are congruent and
which angles are supplementary.
-Every B = B
-Every S = S
-Every S + B = 180˚
***Remember: In order for the angle relationships to work, you must have a pair of
parallel lines cut by a transversal. If the two lines are not parallel, then none of the
relationship hold true.***
Examples:
1. Label all of the angles:
80˚
2. In the diagram below r || s. If m<4 = 2x - 17 and m<1 = 85˚, find the value of x.
s
1 2
3 8
r
7
4
6 5
3, In the diagram below s || r. If m<3 = 4y+30 and the m<7 = 7y + 6, find the value of y.
s
1 2
3 8
r
7
4
6 5
4. In the diagram below j || k. If m<2 = 4x + 7 and m<7 = 5x - 13, what is the value of x?
5. In the diagram below j || k. Find y if m<5 = 68 and m<3 = 3y - 2.
6. In the diagram below j || k. Find x if m<2 = 2x-15 and m<6 = x + 55.
7. In the figure below a || b, m<1 = 94. Find the measure of each angle below. Explain how
you arrived at your answer.
a. m<3:
b. m<5:
c. m<4: