
Public learning track
Transformation-Based Triangle Congruence and Proofs
10th Grade · Math · Open Global Math
6 lessons
Goal
Establish triangle congruence criteria using rigid transformations and write rigorous geometric proofs.
Featured Diagrams
Defining Congruence in Terms of Rigid Motions
6 lessons
0 of 6 done
- 1Defining Congruence in Terms of Rigid MotionsUp nextStart
- 2Proving the SAS and SSS Triangle Congruence CriteriaPremiumNot started yet
- 3Proving the ASA and AAS Triangle Congruence CriteriaNot started yet
- 4Hypotenuse-Leg Congruence in Right TrianglesNot started yet
- 5Writing Two-Column and Flowchart Proofs Using CPCTCNot started yet
- 6Using Congruent Triangle Proofs in ProblemsNot started yet
Standards Covered
- OGM.11.GEO.3Open Global Math Standards 2026™ · Math · Level 11 / High School 2 (Age 15) · Grade 10Define rigid motions (translations, reflections, rotations) and dilations as functions in the coordinate plane; determine symmetries of 2D shapes; analyze compositions of transformations; establish criteria for congruence (SSS, SAS, ASA, AAS, HL) and similarity (AA, SAS, SSS) based on transformations.
- OGM.11.GEO.4Open Global Math Standards 2026™ · Math · Level 11 / High School 2 (Age 15) · Grade 10Prove and apply theorems regarding lines, angles (vertical, parallel transversal angles, perpendicular bisectors), triangles (interior/exterior angle sum, isosceles base angles, midsegments, medians, concurrency, triangle inequality), quadrilaterals (parallelograms, rectangles, rhombuses, squares, trapezoids), and proportional relationships (triangle proportionality, geometric mean with right triangle altitudes).
Curriculum Framework
10th Grade · Math · Open Global Math
1
7 lessons
Logical Foundations, Axioms, and Non-Euclidean Geometry
Analyze undefined terms, construct conditional statements and counterexamples, and compare Euclidean with spherical geometries.
2
8 lessons
Compass, Straightedge, and Dynamic Constructions
Perform precise classical and software-based geometric constructions and verify their theoretical foundations.
3
6 lessons
Rigid Transformations, Coordinate Mappings, and Symmetry
Represent translations, reflections, and rotations as functions on the plane and analyze symmetries and composite motions.
4
6 lessons
Transformation-Based Triangle Congruence and Proofs
Establish triangle congruence criteria using rigid transformations and write rigorous geometric proofs.
5
6 lessons
Parallel Lines, Angles, and Polygon Theorems
Prove theorems regarding lines cut by transversals, perpendicular bisectors, and interior/exterior angles of polygons.
6
6 lessons
Triangle Theorems, Concurrency, and Inequalities
Prove and apply theorems on isosceles triangles, midsegments, centers of concurrency, and triangle inequalities.
7
6 lessons
Dilations, Similarity, and Proportional Reasoning
Define similarity via dilations, establish AA, SAS, and SSS similarity criteria, and prove triangle proportionality theorems.
8
4 lessons
Right Triangle Similarity and Geometric Mean
Prove altitude-to-hypotenuse similarity theorems and use geometric mean relations to derive the Pythagorean Theorem.
9
5 lessons
Quadrilaterals: Properties, Classifications, and Proofs
Prove characterizations of parallelograms, rectangles, rhombuses, squares, and trapezoids.
10
6 lessons
Circle Theorems: Angles, Chords, and Tangents
Prove and apply theorems concerning central, inscribed, and circumscribed angles, tangent lines, and intersecting chords.
11
5 lessons
Inscribed Figures, Circumscribed Circles, and Constructions
Prove properties of cyclic quadrilaterals, construct incircles and circumcircles of triangles, and construct tangent lines.
12
6 lessons
Coordinate Geometry: Formulas, Lines, and Partitions
Derive distance, midpoint, and segment partition formulas, and write equations of parallel and perpendicular lines.
13
6 lessons
Conic Sections in Coordinate Geometry
Derive standard and general equations of circles, parabolas, ellipses, and hyperbolas using distance loci.
14
5 lessons
Coordinate Proofs and Geometric Loci
Prove geometric properties of polygons and loci algebraically using coordinate geometry.
15
5 lessons
Vector Geometry and Operations in 2D
Represent vectors geometrically and algebraically, perform vector operations, and compute magnitudes and unit vectors.
16
5 lessons
Vector Applications and Geometric Theorems
Apply vector algebra to prove classical geometric theorems and model planar geometry problems.