Geometry Midterm Exam Review - Unit 2
Perpendicular Bisector
A perpendicular segment that goes through the midpoint of another segment
HL
Hypotenuse-leg postulate, can only be used in a right triangle
Altitude
A perpendicular segment that connects a vertex with the side opposite from it
Equilateral Triangle
3 Congruent Sides
Acute Triangle
3 angles that are less than 90 degrees
Median
A segment that connects a vertex with the mid point of the opposite side from it
Equianglular Triangle
All angles are congruent and equal 60 degrees
AAS
Angle-angle-side postulate
ASA
Angle-side-angle postulate
Isosceles Triangle
At least 2 congruent sides
Zero Product Property
If a+b=0, then b=0 or a=0 Want: ax^2 + bx +c = 0
Postulate
If two triangles share the following triplets of congruent corresponding points, then the triangles are congruent
Angle-Side Relationships
In a triangle, the largest side is opposite the largest angle and the smallest side is opposite the smallest angle
Scalene Triangle
No congruent sides
ASS
Not a postulate
Triangle Postulates
SSS, SAS, ASA, AAS and HL
Congruency
Same shape and same size
SAS
Side-angle-side postulate
SSS
Side-side-side postulate
Reflexive Property
Some object is congruent to itself
How to write a congruence proof
Step 1: Mark Diagram Step 2: identify the Postulate Step 3: Organize thoughts Step 4: Write Proof, state the given info first Step 5: Reread Proof
Triangle Inequality
The sum of any 2 sides of a triangle that must be greater than the 3rd side
Right Triangle
has one angle that equals 90 degrees
Obtuse Triangle
has one angle that measures more than 90 degrees