Transcript of Angle Relationships & Parallel Lines Pre-Algebra.
Angle Relationships&
Parallel LinesPre-Algebra
Adjacent angles are “side by side” and share a common ray.
45º15º
These are examples of adjacent angles.
55º
35º
50º130º
80º 45º
85º20º
These angles are NOT adjacent.
45º55º
50º100º
35º
35º
Complementary Anglessum to 90°
40°
50°
Complementary angles add up to 90º.
60º
30º40º
50º
Adjacent and Complementary Angles
Complementary Anglesbut not Adjacent
Supplementary Anglessum to 180°
30° 150°
Supplementary angles add up to 180º.
60º120º
40º
140º
Adjacent and Supplementary Angles
Supplementary Anglesbut not Adjacent
Vertical Anglesare opposite one another.
Vertical angles are congruent.
100°
100°
Vertical Anglesare opposite one another.
Vertical angles are congruent.
80°
80°
Lines l and m are parallel.l||m
120°
l
m
120°
120°
120°
Note the 4 angles that measure 120°.
nLine n is a transversal.
Lines l and m are parallel.l||m
60°
l
m
60°
60°
60°
Note the 4 angles that measure 60°.
nLine n is a transversal.
Lines l and m are parallel.l||m
60°
l
m
60°
60°
60°
There are many pairs of angles that are supplementary.
There are 4 pairs of angles that are vertical.
120°
120°
120°
120°
nLine n is a transversal.
If two lines are intersected by a transversal and any of the angle pairs shown below are congruent, then the lines are parallel. This fact is used in the construction of parallel lines.