1. Unit 2 Prior Vocabulary Gallery

2. Parallel Lines
Two lines that lie in the same plane and they do not intersect
Symbol ‖.
In this case r is parallel to s k ‖ s
Parallel lines have the same slope.

3. Congruent
Having the same size, shape and measure.
Notice that each figure below is congruent
to one other figure in the given set of
figures. The congruent pairs are congruent
because they have the same size and
shape, regardless of their orientation (the
way they are "sitting").

4. Perpendicular Lines
Two lines that intersect at a right angle.
The angle equals 90 degrees.

5. Angles that sum up to 180˚ AND make a straight line.
Linear Pair
Angles that sum up to 180˚ AND make a straight line.
NOT a linear pair.
A linear pair is both Adjacent and supplementary angles.

6. Adjacent Angles
Angles in the same plane that have a common side and a common vertex, and don’t overlap.
In the figure above, angle FKI and angle FKH are adjacent angles.

7. Vertical Angles
Opposing angles formed when 2 lines intersect.
In this case angle
EKG is vertical to angle HKF
Notice that the angles have only one point in common, the vertex (K).

8. Transversal
A line that crosses two or more lines.
In this case angle
Line q is a transversal.

9. The angles inside the parallel lines cut by a transversal.
Interior Angles
The angles inside the parallel lines cut by a transversal.
In this example angles 3, 4, 7 and 8 are all interior angles.

10. The angles OUTSIDE the parallel lines cut by a transversal.
Exterior Angles
The angles OUTSIDE the parallel lines cut by a transversal.
In this example angles 1, 2, 5 and 6 are all exterior angles.

11. Alternate Interior Angles
Pairs of angles inside the parallel lines on opposite sides of the transversal. Alternate Interior Angles are congruent.
In this example angle 3 is alternate interior to angle 7
AND
Angle 8 is alternate interior to angle 4

12. Alternate Exterior Angles
Pairs of angles OUSTIDE the parallel lines on opposite sides of the transversal. Alternate Exterior Angles are congruent.
In this example angle 2 is alternate EXTERIOR to angle 6
AND
Angle 1 is alternate exterior to angle 5

13. Same-Side Interior Angles
Angles in one side of the transversal and inside the parallel lines.
Angles 8 and 7 are
same-side interior angles AND
angles 3 and 4 are same-side interior angles.

14. Consecutive Interior Angles
Tow angles that are in the same side of the transversal and in the interior of two parallel lines.
Angles 1 and 3 are
consecutive interior angles and
angles 2 and 4 are consecutive
interior angles.

15. Same-Side EXTERIOR Angles
Angles in one side of the transversal and OUTSIDE of the parallel lines.
Angles 1 and 6 are
same-side exterior angles AND
angles 2 and 5 are same-side exterior angles

16. Corresponding Angles
Angles on the same side of the transversal. Relative Position
Angles 8 and 6 are
Corresponding angles AND
angles 2 and 4 are corresponding angles

17. Related to itself / equal to itself.
Reflexive Property
Related to itself / equal to itself.
In this case the triangles share the SAME side BD.
In this example the triangles have the SAME angle in common angle A.

18. Similar
Having the same shape; corresponding sides are proportional and corresponding angles are equal.

19. STOP HERE

21. Complementary Angles
Two angles whose sum is 90º.
In the example to the right,
notice that at all times, angle
BAT + angle CAT = 90º.The
diagram to the left is the
typical representation of
complementary angle,
but the angles do not have to
be adjacent (as shown here)
To be complementary.

22. Supplementary Angles
Two angles whose sum is 180.
Notice that since angle ABC is
a straight angle, meaning that
its measure is 180 degrees,
then angle ABG + angle CBG
= 180 degrees. Therefore, we
can say that angles ABG and
CBG are supplementary.

23. Part 3
Polygon Vocabulary

24. Equiangular
The property of a polygon whose angles are
all congruent.
For example, an equilateral triangle is
equiangular since its interior angles are equal
(to 60 degrees). In general, all regular polygons
such as equilateral triangle, square, pentagon,
and hexagon are equiangular.

25. Equilateral
The property of a polygon whose sides
are all congruent.

26. Regular Polygon
A polygon that is both equilateral and
equiangular. Meaning same size angles
and sames size sides.

27. Diagonal
A segment that joins two nonconsecutive vertices of a polygon.