Geometry
Name: _________________________
Date: _______________ Per.: ______
MIDTERM EXAM: Chapter 4 Review – Congruent Triangles
Key Concepts & Skills










Classify triangles by angles and sides (4.1)
Apply the triangle sum theorem and the exterior angle theorem to find the measures of angles of
triangles (4.1)
Identify congruent corresponding parts of triangles and write congruence statements (4.2)
Use triangle congruence to find measures of angles or sides (4.2)
Prove triangles are congruent using congruence postulates or theorems: SSS, SAS, ASA, and
AAS (4.3 and 4.4)
Decide whether it is possible to prove triangles are congruent and, if so, tell which postulate or theorem
applies (4.3 and 4.4)
Use congruent triangles to write proofs (4.5)
CPCTC—Corresponding Parts of Congruent Triangles are Congruent (4.5)
Plan for a proof (4.5)
Write two-column or paragraph proofs (4.3—4.5)
Key Points
Triangles can be classified by their sides and by their angles.
Triangle Sum Theorem
MD/1-08/Ch. 4 MT Review
1
Geometry
When two figures are congruent their corresponding sides and
corresponding angles are congruent. In the diagram ABC  XYZ.
Triangle Congruence Theorems and Postulates
CPCTC – Corresponding Parts of Congruent Triangles are Congruent
Only used to prove corresponding parts of two triangles are congruent IF the two triangles are known to be
congruent or AFTER the two triangles are proven to be congruent.
Problems
I. Classify the triangle by sides and angles.
MD/1-08/Ch. 4 MT Review
2
Geometry
II. Congruence and Triangles. Use the figure to the right of ABC and XYZ
1.
2.
III. Proving Triangles are Congruent.
1) Decide whether it is possible to prove that the triangles are congruent. If it is possible, tell which
postulate or theorem you would use.
a)
b)
c)
IV. Isosceles, Equilateral, and Right Triangles. Find the value of x.
1)
2)
3)
4)
MD/1-08/Ch. 4 MT Review
3
Geometry
V. Proofs. Write a two-column proof.
1)
2)
3)
MD/1-08/Ch. 4 MT Review
4