Mathematics · Suggested grades 9–11

Geometry
Course map.

Use definitions, transformations and logical arguments to investigate shape, measurement and spatial relationships.

Grade ranges and the sequence below are suggestions, not graduation requirements. Choose by readiness and your school’s course plan.

Before this course

Solve linear equations.
Use coordinates, basic angle relationships and the Pythagorean relationship.

Where it can lead

Connects to design, measurement, construction and later trigonometry. Schools arrange geometry and algebra in different sequences.

A suggested progression

Transformations and reasoning
Congruence, similarity and right triangles
Circles and three-dimensional measurement

Six starter mini-lessons sample selected skills. This is not a full year of daily instruction, complete standards coverage, an accredited course or graduation credit. Grade placement and unit order are planning guidance, not requirements.

Unit → Lesson

Your learning path

3 units · 6 starter lessons

Unit 1: Congruence through motion and reasoning

Build geometric justification from transformations and triangle structure.

Before this unit: Coordinate plane Angle vocabulary

Congruence as a Sequence of Rigid Motions35 minutes · HSG.CO.B.6
Why SAS Determines a Triangle35 minutes · HSG.CO.B.8

Browse this unit →

Unit 2: Similarity and right-triangle measures

Connect proportional figures to angle-dependent ratios.

Before this unit: Triangle geometry Algebra I equations

Similar Triangles and a Shadow Estimate35 minutes · HSG.SRT.B.5
Right-Triangle Trigonometry in a Diagram40 minutes · HSG.SRT.C.8

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Unit 3: Circles and three-dimensional measurement

Relate radius, angles and volume to scale.

Before this unit: Circle area Square and cube units

Arc Length, Radians and Sector Area35 minutes · HSG.C.B.5
Volume Comparisons for Solid Designs35 minutes · HSG.GMD.A.3

Browse this unit →

A course map. A practical starting point.

These 138 original mini-lessons sample 23 courses for grades 9–12. They do not provide a full year of daily lessons, complete standards coverage, accredited courses or graduation credit. Suggested grade ranges, prerequisites and unit order are planning guidance; school pathways and elective availability vary. Calculus is excluded.

Subject-content contribution identifies a selected math, English, science or world-language skill. Common Core high school math uses conceptual categories, not universally assigned courses or grades. Mapping a skill to a course is an instructional choice. (+) Additional preparation identifies standards the official source marks for advanced study.

English uses the 9–10 and 11–12 bands; there are no separate Common Core English 9, 10, 11 or 12 codes. NGSS references identify the high school band and partial performance-expectation contributions.

Supporting Common Core literacy connection applies only to an actual reading, writing or communication activity. It does not establish science, social studies or elective subject-content alignment. Unverified subject-content mappings are labeled explicitly.

Spanish uses World-Readiness language standards, identified by their official names in the current summary. Common Core does not measure Spanish proficiency. Supported lesson practice is distinct from an independently assessed proficiency rating and from the course title.

Use North Carolina’s Standard Course of Study ↗ for local planning. No NC alignment is claimed without a verified crosswalk. Each mapping links to official wording, records its verification date and explains the part practiced.