math

Median

Median

Vertex to midpoint of opposite sides

Altitude

Vertex to opposite side of the triangle at a 90 degree angle. Shows the height of the triangle

Perpendicular Bisector

Bisects a side of a triangle (cut it perfectly in half) at a 90 degree angle.

Angle Bisector

Segment that bisects each vertex (angle) in a triangle (cuts the angle perfectly in half)

Midsegment

Segment that connects the midpoints of two sides of a triangle. The midsegment is half the side it's parallel to.

Centroid

Point where all three medians intersect. Divides the medians up into a 2:1 ratio.

Orthocenter

Point where all three altitudes intersect.

Circumcenter

Point where all three perpendicular bisectors intersect. Circumcenter is the same distance away from all three vertices.

Incenter

Point where the three angle bisectors intersect. The incenter is the same distance away from all three sides of a triangle . . . AND forms a 90 degree angle with the sides.

ASA

Does prove triangle congruency.

SAS

Does prove triangle congruency

SSS

Does prove triangle congruency

AAS

Does prove triangle congruency

SSA

Does NOT prove triangle congruency

AAA

Does NOT prove triangle congruency

How many degrees are in a triangle?

180⁰

Alternate Interior Angles

Are Congruent

Alternate Exterior Angles

Are Congruent

Corresponding Angles

Are Congruent

Vertical Angles

Are Congruent

supplementary angles

add to 180 degrees

Reflexive Property

the property that says that anything is equal to (or congruent to) itself

Symmetric Property

if a=b, then b=a

CPCTC

Corresponding Parts of Congruent Triangles are Congruent

Parallelogram Properties