Chapter 1 Flashcards
(53 cards)
what is a segment?
a part of a line with two endpoints.
what is a ray?
one endpoint that extends in one direction.
what are opposite rays?
two rays that go in opposite directions and have the same endpoint.
what does collinear mean?
points are on the same line
what does coplanar mean?
points are on the same plane.
what is an intersection?
two or more geometric figures have on or more points in common.
what is a postulate?
a rule that is accepted w/o proof
what is a theorem?
a rule that can be proven true
what is postulate 1.1?
ruler postulate
what does the ruler postulate say?
we can measure segments.
what does congruent mean?
same measurements.
what can you say when three points are collinear?
one point is between the other two.
what is postulate 1.2?
segment addition postulate
what does the segment addition postulate say?
if B is between A and C, then AB + BC = AC
if AB + BC = AC, then B is between A and C.
What is the distance formula?
d = \sqrt{(x2 - x1)2 + (y2-y1)2}
what is a midpoint?
the point that divides a segment into congruent segments.
what is a segment bisector?
a point, line, line segment, or plane that intersects the segment of its midpoint.
what does identifying something means?
to label it
what is the midpoint formula?
(x1+x2/2, y1+y2/2)
what is an angle?
two different rays w/ the same endpoint
what is the vertex of the angle?
the endpoint of the angle
where must the vertex be when labeling an angle?
the middle
what is postulate 1.3
protractor postulate
what does the protractor postulate say?
you can measure angles in degrees.
