GE = 2x – 7 GF = x + 4. What is GD? Solve for the variable

Bellringer P 23 top 10 lines

Triangle Congruence

Sections 4-2, 4-3, 4-6

SSS

Example

NOTE:

• The only time two sides are unmarked and congruent are when they are shared sides (like in the previous example)

• This is because of the Reflexive property of congruence

SAS

Note:

• The congruent angle MUST BE between the two congruent sides.

• The only time unmarked angles are congruent is when they are vertical (they make the X)

Try it

Again

Bellringer

ASA

NOTE:

• The congruent side needs to be between the congruent angles.

AAS

NOTE

• The third angles theorem states that when two angles of a triangle are congruent to two angles of a different triangle then the third angles are also congruent.

• This connects AAS to ASA

Example:

WRITING A PROOF FOR TRIANGLE CONGRUENCE

RIGHT TRIANGLES

HL

NOTE:

• This only works for right triangles• MUST have congruent hypotenuses• MUST have a pair of congruent legs

Example