# Geometry Vocab. Ch.3

geometry vocabulary chapter 3

## Terms

undefined, object
copy deck
Alternate interior angles
Two non adjacent interior angles on opposite sides of the transversal
Pentagon
5 sides
Decagon
10 sides
Equilateral triangle
all sides congruent
Transversal
a line that intesects two or more coplanar lines in different points
Same-side interior angles
two interior angles on the same side of the transversal
Ways to prove lines are parallel
1.) Show that a pair of corresponding angles are congruent. 2.)Show that a pair of alternate interior angles are congruent. 3.) Show that a pair of same-side interior angles are congruent. 4.) In a plane show that both lines are perpendicular to the third line. 5.)Show that both lines are parallel to a third line
Triangle
3 sides
Parallel lines
coplanar lines that do not intersect
Hexagon
6 sides
n-gon
n number of sides
Skew lines
non-coplanar lines that are not parallel or intersecting
Inductive Reasoning
Conclusions bases on several past observations; Conclusion is probably true, but not necessarily true
Octagon
8 sides
Isosceles Triangle
At least two sides congruent
Deductive Reasoning
Conclusion bases on accepted statemenets(definations, postulates, previous theorems, corollaries, and given information); conclusions must be true if hypothesis is true
Scalene Triangle
no sides congruent
Corresponding angles
two angles in corresponding positions relative to the two lines