This is a draft cheat sheet. It is a work in progress and is not finished yet.
VOCAB
Segment 
Part of a line consisting of two end points and the points between them 
Ray 
Part of a line consisting of an end point and all the points to one side 
Parallel Lines 
Coplaner lines that do not intersect 
Skew Lines 
Noncoplaner lines that do not intersect 
Parallel Planes 
Planes that do not intersect 
Midpoint 
Point on a segment that divides a segment into 2 congruent segments 
Acute Angle 
Greater than 0 and less than 90 
Right angle 
90 degree angle 
Obtuse angle 
Angle greater than 90 but less than 180 
Congruent angles 
Angles with the same measure 
Vertical angles 
Opposite angles formed by intersecting lines 
Complementary angles 
2 angles that add up to 90 degrees 
Supplementry angles 
2 angles that add up to 180 degrees 
Transversal 
A line that intersects 2 or more coplaner lines at distinct points 
Acute Triangle 
All angles are acute 
Right Triangle 
One right angle 
Obtuse Triangle 
One obtuse angle 
Equalateral Triangle 
All sides are congruent 
Isosceles Triangle 
2 congruent sides 
Scalene Triangle 
No congruent sides 
Circumcenter 
The point of concurrency of the perpendicular bisectors of a triangle 
Altitude 
Height of a triangle 
Centroid 
Point of concurrency of the medians; always lies within the triangle 
Quadrilateral 
Polygon with 4 sides 
Equidistant 
Exact same distance 
Don't kill me if one of these are wrong, I just have what Mrs. Craig taught us.


Other things you "need" to know
Congruence Statements 
ASA, SAS, SSS, AAS, HL 
Pythagorean Theorem 
FOR RIGHT TRIANGLES ONLY 
Theorem 1 
Parallel lines are always the same distance apart 
Theorem 2 
If parallel lines cut one transversal into equal parts, it cuts any transversal into equal parts 
