Free printable worksheet

Congruent Triangles Worksheet

Twelve problems identifying triangle congruence theorems and using corresponding parts.

GeometryGrades 8-104 pagesAnswer key included

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What this worksheet includes

Twelve problems identifying triangle congruence theorems and using corresponding parts.
4-page printable PDF with a complete answer key
Designed for Grades 8-10 geometry practice
Available as an immediate no-email download

How to use it

Use this congruent triangles worksheet for guided practice, independent review, homework, tutoring sessions, or a quick skills check. The spacious layout is designed to leave room for students to show their work rather than guess from crowded answer choices.

After students finish, compare their reasoning with the included answer key. When an answer is incorrect, have the student locate the first step where their work changed direction before trying the problem again.

Who this practice is for

This resource is designed for grades 8-10 students working on geometry. Teachers, tutors, homeschool families, and parents can preview the first page before deciding whether the level and spacing fit the student.

Looking for a broader sequence? Browse all Geometry worksheets.

Topic guide

How to approach congruent triangles

Congruent Triangles practice is most effective when students identify the governing definition, theorem, or rule before beginning a calculation. Twelve problems identifying triangle congruence theorems and using corresponding parts.

This geometry set moves from direct applications into mixed review. Students should preserve exact values, label each important step, and use the answer key to locate the first point where an incorrect solution changes direction.

Learning objectives

Recognize the central rules and representations used in congruent triangles
Apply an efficient procedure to solve congruent triangles problems
Check results using notation, substitution, estimation, or a relevant inverse process

Skills to review first

Core vocabulary connected to congruent triangles
Accurate arithmetic and algebraic simplification
Reading mathematical notation and showing work in a logical sequence

Worked example

Follow the reasoning step by step

Plan and solve a representative congruent triangles problem from Part A.

List the given information and state what must be found.
Select the definition, theorem, formula, or procedure that applies to congruent triangles.
Substitute or transform carefully, keeping one logical change on each line.
Check the result against the original conditions and include units or restrictions when needed.

Solution: A complete solution includes the correct result and enough reasoning to verify it.

Try before downloading

Three sample problems

Work each problem, then open the answer to check your result.

Problem 1 · foundations

$\begin{gathered}AB=DE,\ BC=EF,\ AC=DF.\\\text{Prove }\triangle ABC\cong\triangle DEF\\\text{ and name the congruence theorem.}\end{gathered}$

Show answer

$\triangle ABC\cong\triangle DEF\text{ by SSS}$

Problem 2 · skill practice

$\begin{gathered}AB=DE,\ BC=EF,\ \angle A=\angle D.\\\text{Is this enough to prove the triangles congruent?}\\\text{Explain why or why not.}\end{gathered}$

Show answer

$\text{No; SSA does not guarantee congruence}$

Problem 3 · mixed review

$\begin{gathered}RS=UV,\ ST=VW,\ RT=UW.\\\text{Write a congruence statement and}\\\text{name the congruence theorem.}\end{gathered}$

Show answer

$\triangle RST\cong\triangle UVW\text{ by SSS}$

Error check

Common mistakes to watch for

Beginning a calculation before identifying the relevant rule or given information
Dropping a sign, unit, restriction, or exact-value symbol during simplification
Comparing only the final answer instead of checking the first incorrect step

Congruent Triangles Worksheet

What this worksheet includes

How to use it

Who this practice is for

How to approach congruent triangles

Learning objectives

Skills to review first

Follow the reasoning step by step

Three sample problems

AB=DE, BC=EF, AC=DF.Prove △ABC≅△DEF and name the congruence theorem.\begin{gathered}AB=DE,\ BC=EF,\ AC=DF.\\\text{Prove }\triangle ABC\cong\triangle DEF\\\text{ and name the congruence theorem.}\end{gathered}

AB=DE, BC=EF, ∠A=∠D.Is this enough to prove the triangles congruent?Explain why or why not.\begin{gathered}AB=DE,\ BC=EF,\ \angle A=\angle D.\\\text{Is this enough to prove the triangles congruent?}\\\text{Explain why or why not.}\end{gathered}

RS=UV, ST=VW, RT=UW.Write a congruence statement andname the congruence theorem.\begin{gathered}RS=UV,\ ST=VW,\ RT=UW.\\\text{Write a congruence statement and}\\\text{name the congruence theorem.}\end{gathered}

Common mistakes to watch for

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$\begin{gathered}AB=DE,\ BC=EF,\ AC=DF.\\\text{Prove }\triangle ABC\cong\triangle DEF\\\text{ and name the congruence theorem.}\end{gathered}$

$\begin{gathered}AB=DE,\ BC=EF,\ \angle A=\angle D.\\\text{Is this enough to prove the triangles congruent?}\\\text{Explain why or why not.}\end{gathered}$

$\begin{gathered}RS=UV,\ ST=VW,\ RT=UW.\\\text{Write a congruence statement and}\\\text{name the congruence theorem.}\end{gathered}$