
Public learning track
Circles: Circumference, Area, and Circular Rings
6th Grade · Math · Open Global Math
11 lessons
Goal
Identify parts of a circle, derive the constant ratio pi (π = C/d), and calculate circumference, circle area, sector angles, and annulus ring areas.
Featured Diagrams
Identifying Radius, Diameter, and Chord on a Figure
11 lessons
0 of 11 done
- 1Identifying Radius, Diameter, and Chord on a FigureUp nextStart
- 2Identifying Arcs, Sectors, and Segments of CirclesPremiumNot started yet
- 3Investigating the Ratio of Circumference to Diameter (π)Not started yet
- 4Calculating Circumference Using Radius and DiameterNot started yet
- 5Finding Radius and Diameter from Given CircumferenceNot started yet
- 6Deriving the Circle Area Formula by Sector RearrangementNot started yet
- 7Calculating the Area of Circles with Radius and DiameterNot started yet
- 8Calculating Radius and Diameter from Circle AreaNot started yet
- 9Calculating Perimeters and Areas of Semicircles and QuadrantsNot started yet
- 10Calculating the Area of Circular Rings and Annulus ShapesNot started yet
- 11Composite Figures Combining Polygons and Circular RegionsNot started yet
Standards Covered
- OGM.7.GEO.2Open Global Math Standards 2026™ · Math · Level 7 / Grade 6 (Age 11) · Grade 6Identify parts of a circle (radius, diameter, chord, circumference, sector); establish the constant ratio π = C/d and calculate the circumference and area of circles and circular rings.
- OGM.7.GEO.1Open Global Math Standards 2026™ · Math · Level 7 / Grade 6 (Age 11) · Grade 6Derive and apply area formulas for triangles, special quadrilaterals (rectangles, parallelograms, rhombuses, trapezoids), and irregular polygons by composition into rectangles and decomposition into triangles; solve practical area and perimeter problems involving unit consistency.
Curriculum Framework
6th Grade · Math · Open Global Math
1
10 lessons
Angle Relationships and Geometric Reasoning
Identify, classify, and calculate unknown angle measures using complementary, supplementary, vertical, adjacent, and intersecting line relationships with algebraic equations.
2
11 lessons
Triangles, Polygons, and Angle Theorems
Investigate, classify, and calculate interior and exterior angle sums for triangles, special quadrilaterals, and regular and irregular n-gons.
3
8 lessons
Geometric Constructions and Triangle Inequalities
Construct triangles and geometric figures with compass and straightedge, apply the triangle inequality theorem, and construct angle and segment bisectors.
4
10 lessons
Area and Perimeter of Two-Dimensional Polygons
Derive and apply formulas for perimeter and area of triangles, parallelograms, rhombuses, and trapezoids with consistent metric and customary units.
5
7 lessons
Decomposing Figures and Composite Area
Calculate the area of complex, composite, and irregular 2D polygons by additive composition and subtractive decomposition.
6
11 lessons
Circles: Circumference, Area, and Circular Rings
Identify parts of a circle, derive the constant ratio pi (π = C/d), and calculate circumference, circle area, sector angles, and annulus ring areas.
7
10 lessons
Cartesian Coordinate Plane: Distances and Polygons
Plot points in all four quadrants, calculate horizontal and vertical segment lengths using absolute value, and construct polygons to determine coordinate perimeter and area.
8
8 lessons
Rigid Transformations on the Coordinate Plane
Perform, describe, and analyze translations, reflections, and rotations of 2D shapes on coordinate grids using algebraic mapping rules.
9
7 lessons
Dilations, Scale Factors, and Similarity
Perform and analyze dilations centered at the origin or arbitrary points, calculate scale factors, and explore properties of similar geometric figures.
10
7 lessons
Symmetry Transformations and Tessellations
Analyze line and rotational symmetry in 2D shapes, determine orders of rotation, and investigate regular, semi-regular, and artistic tessellations.
11
7 lessons
Three-Dimensional Solids, Cross-Sections, and Views
Identify 3D solid structures, interpret and draw 2D orthographic projections (top, front, side), and determine shapes formed by 2D cross-sections.
12
7 lessons
Scale Drawings, Maps, and Bearings
Construct and interpret scale drawings, architectural floor plans, map routes, three-figure bearings, and cardinal directional bearings.
13
9 lessons
Two-Dimensional Nets and Surface Area of Solids
Unfold 3D solids into 2D nets and calculate total and lateral surface areas of rectangular prisms, triangular prisms, pyramids, and cylinders.
14
8 lessons
Volume of Prisms, Unit Cubes, and Capacity Conversions
Calculate the volume of cubes and right rectangular prisms with fractional and decimal edges using packing and formulas, and convert between cubic volume and liquid capacity.