Understanding ratios of areas of inscribed figures using interactive diagrams
http://standards.nctm.org/document/eexamples/chap7/7.3/
A lesson plan for Grades 9–12 Technical Mathematics 1, Geometry, Integrated Mathematics 3, Technical Mathematics 2, Integrated Mathematics 4, Pre-Calculus, and Algebra 1
This example illustrates how students can understand connections between algebra and geometry using dynamic and interactive geometric figures. They can develop an understanding of how to justify geometric relationships in a technological environment.
E-Math Investigations are selected e-examples from the electronic version of the Principles and Standards of School Mathematics (PSSM). The e-examples are part of the electronic version of the PSSM document. Given their interactive nature and focused discussion tied to the PSSM document, the e-examples are natural companions to the i-Math investigations.
North Carolina Curriculum Alignment
Mathematics (2004)
Grades 9–12 — Algebra 1
- Goal 2: Geometry and Measurement - The learner will describe geometric figures in the coordinate plane algebraically.
- Objective 2.01: Find the lengths and midpoints of segments to solve problems
Grades 9–12 — Geometry
- Goal 1: Number and Operations - The learner will perform operations with real numbers to solve problems.
- Objective 1.02: Use length, area, and volume of geometric figures to solve problems. Include arc length, area of sectors of circles; lateral area, surface area, and volume of three-dimensional figures; and perimeter, area, and volume of composite figures.
Grades 9–12 — Integrated Mathematics 3
- Goal 3: Algebra - The learner will use relations and functions to solve problems.
- Objective 3.02: Use quadratic functions and inequalities to model and solve problems; justify results.
- Solve using tables, graphs, and algebraic properties.
- Interpret the constants and coefficients in the context of the problem.
- Objective 3.02: Use quadratic functions and inequalities to model and solve problems; justify results.
Grades 9–12 — Integrated Mathematics 4
- Goal 2: Geometry and Measurement - The learner will describe geometric figures in the coordinate plane algebraically.
- Objective 2.02: Estimate the area and volume of continuously varying quantities.
- Goal 4: Algebra - The learner will use relations and functions to solve problems.
- Objective 4.02: Use recursively-defined functions to model and solve problems.
- Find the sum of a finite sequence.
- Find the sum of an infinite sequence.
- Determine whether a given series converges or diverges.
- Translate between recursive and explicit representations.
- Objective 4.02: Use recursively-defined functions to model and solve problems.
Grades 9–12 — Pre-Calculus
- Goal 1: Number and Operations - The learner will describe geometric figures in the coordinate plane algebraically.
- Objective 1.01: Transform relations in two dimensions; describe the results algebraically and geometrically.
Grades 9–12 — Technical Mathematics 1
- Goal 2: Geometry and Measurement - The learner will measure and apply geometric concepts to solve problems.
- Objective 2.03: Use the length, area, and volume of geometric figures to solve problems. Include arc length, area of sectors of circles; lateral area, surface area, and volume of three-dimensional figures; and perimeter, area, and volume of composite figures.
Grades 9–12 — Technical Mathematics 2
- Goal 2: Algebra - The learner will use relations and functions to solve problems.
- Objective 2.01: Use quadratic equations to model and solve problems; justify results.
- Solve using tables, graphs, and algebraic properties.
- Interpret the constants and coefficients in the context of the problem.
- Objective 2.01: Use quadratic equations to model and solve problems; justify results.



