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Congruent Triangles - Worksheet 3 - 10th Grade

Easy

Prove triangle congruence using congruence criteria (Easy)

15 problems · 25-30 minutes · Skills: triangles, congruence, proofs

About This Worksheet

This easy-level worksheet contains 15 problems designed for 10th Grade students practicing congruent triangles. Easy worksheets use simpler numbers and straightforward problem types to build confidence and reinforce foundational skills.

Triangle congruence is the engine behind a huge portion of geometric proof. From proving that diagonals of a parallelogram bisect each other to establishing properties of isosceles triangles, CPCTC and the congruence criteria are used repeatedly throughout the course and in subsequent math courses.

  • Apply SSS, SAS, ASA, AAS, and HL congruence criteria to determine if triangles are congruent
  • Write two-column proofs to prove triangle congruence
  • Use CPCTC to conclude that corresponding parts of congruent triangles are congruent
  • Write correct congruence statements matching corresponding vertices in order
  • Identify which congruence criterion applies given marked diagrams or listed information

How to Solve: Worked Example

Example Problem: Two triangles have three pairs of congruent sides. Which postulate proves congruence?
Solution Steps:
  1. Three pairs of sides are given, and no angles.
  2. The postulate matching three sides is Side-Side-Side.
  3. So the answer is SSS.
Answer: SSS
Tip: The letters describe what you are given, in order around the triangle.
1
What abbreviation states that corresponding parts of congruent triangles are congruent?
2
What does the A stand for in ASA?
3
Do congruent triangles have equal area?
4
Two angles and a non-included side. Which theorem?
5
In SAS, where must the angle be?
6
Two sides and the included angle. Which postulate?
7
HL applies only to which kind of triangle?
8
Right triangles with congruent hypotenuse and one leg. Which theorem?
9
Congruent triangles have congruent corresponding what?
10
In ASA, where must the side be?
11
What does the S stand for in SSS?
12
Three pairs of congruent sides. Which postulate proves congruence?
13
Are all congruent triangles also similar?
14
Two angles and the included side. Which postulate?
15
What abbreviation states that corresponding parts of congruent triangles are congruent?

Answer Key

1. CPCTC2. angle3. Yes4. AAS5. between the two sides6. SAS7. right triangles8. HL9. sides and angles10. between the two angles11. side12. SSS13. Yes14. ASA15. CPCTC

Frequently Asked Questions

How do I download this congruent triangles - worksheet 3 worksheet?

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How do I find worksheets at different difficulty levels?

Each subtopic has 10 worksheets: Worksheets 1-3 are Easy, 4-7 are Medium, and 8-10 are Hard. Start with Easy worksheets to build confidence, then progress to harder ones.

What skills does this triangles worksheet cover?

This worksheet focuses on triangles, congruence, proofs. It is designed for 10th Grade students and provides structured practice through varied problem types with a worked example to guide students before they begin.

Can I use this worksheet in my classroom?

Yes. All worksheets on K12Worksheets are free for classroom use. You can print copies for your entire class. With 10 worksheets per subtopic at three difficulty levels, you have plenty of options for differentiated instruction and individualized practice.

How many problems are on this worksheet?

This worksheet contains 15 problems. It typically takes 25-30 minutes to complete. An answer key with all solutions is included so parents and teachers can check work quickly.