# Congruent Triangles

This is one lesson in a larger Unit Plan that introduces triangular relationships through the lens of building a treehouse with a variety of triangular characteristics.  It has proofs, real world problems, constructions, a unit project, assessments, and more. In Lesson 18, “Congruent Triangles",  students investigate the conditions that make triangles congruent including SSS, AAA, SAS, ASA, AAS, and SSA. There are two patty paper investigations, a video resource, and real world problems. The entire unit plan can be found here. This lesson plan has an investigation into SSS, SAS, ASA, AAS, HL and CPCTC with patty paper. There are also practice worksheets and a series of real world problems. Grouping could be used to help with differentiation. The teacher section suggests numerous visual sources including a video.

### Standards & Objectives

CCSS.ELA-Literacy.RF.1.4
Read with sufficient accuracy and fluency to support comprehension.
CCSS.ELA-Literacy.RI.1.1
CCSS.ELA-Literacy.RI.1.4
Ask and answer questions to help determine or clarify the meaning of words and phrases in a text.
CCSS.ELA-Literacy.RI.1.7
Use the illustrations and details in a text to describe its key ideas.
CCSS.ELA-Literacy.RL.1.1
CCSS.ELA-Literacy.RL.1.2
Retell stories, including key details, and demonstrate understanding of their central message or lesson.
CCSS.ELA-Literacy.RL.1.7
Use illustrations and details in a story to describe its characters, setting, or events.
CCSS.ELA-Literacy.SL.1.1
Participate in collaborative conversations with diverse partners about grade 1 topics and texts with peers and adults in small and larger groups.
CCSS.ELA-Literacy.SL.1.3
CCSS.ELA-Literacy.SL.1.4
Describe people, places, things, and events with relevant details, expressing ideas and feelings clearly.
CCSS.ELA-Literacy.SL.2.4
Tell a story or recount an experience with appropriate facts and relevant, descriptive details, speaking audibly in coherent sentences.
CCSS.ELA-Literacy.SL.3.1
Engage effectively in a range of collaborative discussions (one-on-one, in groups, and teacher-led) with diverse partners on grade 3 topics and...
CCSS.ELA-Literacy.SL.3.4
Report on a topic or text, tell a story, or recount an experience with appropriate facts and relevant, descriptive details, speaking clearly at an...
CCSS.ELA-Literacy.SL.4.1
Engage effectively in a range of collaborative discussions (one-on-one, in groups, and teacher-led) with diverse partners on grade 4 topics and...
CCSS.ELA-Literacy.SL.4.4
Report on a topic or text, tell a story, or recount an experience in an organized manner, using appropriate facts and relevant, descriptive details...
CCSS.ELA-Literacy.W.1.5
With guidance and support from adults, focus on a topic, respond to questions and suggestions from peers, and add details to strengthen writing as needed.
CCSS.ELA-Literacy.W.1.7
Participate in shared research and writing projects (e.g., explore a number of "how-to" books on a given topic and use them to write a sequence of...
CLE 3108.4.2
Describe the properties of regular polygons, including comparative classification of them and special points and segments.
CLE 3108.4.3
Develop an understanding of the tools of logic and proof, including aspects of formal logic as well as construction of proofs.
CLE 3108.4.4
Develop geometric intuition and visualization through performing geometric constructions with straightedge/compass and with technology.
GLE 0101.1.2
Employ a variety of strategies to decode words and expand vocabulary.
GLE 0101.2.1
Develop critical listening skills essential for comprehension, problem solving, and task completion.
GLE 0101.2.2
Develop critical speaking skills essential for effective communication.
GLE 0101.6.2
Identify the main ideas and supporting details of informational text.
GLE 0101.6.3
Recognize that a variety of graphics can support informational text.
GLE 0101.8.2
Employ a variety of basic reading comprehension strategies.
GLE 0101.8.3
GLE 0201.2.2
Develop critical speaking skills essential for effective communication.
GLE 0301.2.1
Continue to develop basic listening skills necessary for communication.
GLE 0301.2.2
Continue to develop basic speaking skills necessary for communication.
GLE 0401.2.1
Continue to develop oral language skills necessary for communication.
GLE 0401.2.2
Continue to develop listening skills necessary for communication.
TSS.ELA.1.FL.F.5
Read with sufficient accuracy and fluency to support comprehension.
TSS.ELA.1.RI.IKI.7
Either orally or in writing when appropriate, use the illustrations and words in a text to describe its key ideas.
TSS.ELA.1.RI.IKI.8
Identify the reasons an author provides to support points in a text.
TSS.ELA.1.RI.KID.1
TSS.ELA.1.RI.KID.2
Identify the main topic and retell key details of a text.
TSS.ELA.1.RL.IKI.7
Either orally or in writing when appropriate, use illustrations and words in a text to describe its characters, setting, or events.
TSS.ELA.1.RL.KID.1
TSS.ELA.1.RL.KID.2
Retell stories, including key details, and demonstrate understanding of their central message or lesson.
TSS.ELA.1.SL.CC.1
Participate with varied peers and adults in collaborative conversations in small or large groups about appropriate 1st grade topics and texts.
TSS.ELA.1.SL.CC.3
TSS.ELA.1.SL.PKI.4
Describe people, places, things, and events with relevant details, expressing ideas and feelings clearly.
TSS.ELA.1.W.PDW.5
With guidance and support from adults, focus on a topic, respond to questions and suggestions from others, and add details to strengthen writing as needed.
TSS.ELA.1.W.RBPK.7
Participate in shared research and writing projects, such as exploring a number of how to books on a given topic and using them to write a sequence of...
TSS.ELA.2.SL.PKI.4
Tell a story or recount an experience with appropriate facts and relevant, descriptive details, speaking audibly in coherent sentences.
TSS.ELA.3.SL.CC.1
Prepare for collaborative discussions on 3rd grade level topics and texts; engage effectively with varied partners, building on others' ideas and...
TSS.ELA.3.SL.PKI.4
Report on a topic or text, tell a story, or recount an experience with appropriate facts and relevant, descriptive details, speaking clearly at an...
TSS.ELA.4.SL.CC.1
Prepare for collaborative discussions on 4th grade level topics and texts; engage effectively with varied partners, building on others' ideas and...
TSS.ELA.4.SL.PKI.4
Report on a topic or text, tell a story, or recount an experience in an organized manner, using appropriate facts and relevant, descriptive details to...

Alignment of this item to academic standards is based on recommendations from content creators, resource curators, and visitors to this website. It is the responsibility of each educator to verify that the materials are appropriate for your content area, aligned to current academic standards, and will be beneficial to your specific students.

Essential and guiding questions:

How are congruent triangles and similar triangles the same and different?

How are congruence relationships useful in everyday life?

### Lesson Variations

Blooms taxonomy level:
Understanding

Contributors: