| Students identify, classify, compare and analyze characteristics, properties and relationships of one-, two- and three-dimensional geometric figures and objects. Students use spatial reasoning, properties of geometric objects, and transformations to analyze mathematical situations and solve problems. | | Indicators for grade 10 | | 1. | Formally define and explain key aspects of geometric figures, including:
a. interior and exterior angles of polygons;
b. segments related to triangles (median, altitude, midsegment);
c. points of concurrency related to triangles (centroid, incenter, orthocenter, and circumcenter); and
d. circles (radius, diameter, chord, circumference, major arc, minor arc, sector, segment, inscribed angle). (ORC Resources) | | 2. | Recognize and explain the necessity for certain terms to remain undefined, such as point, line and plane. (ORC Resources) | | 3. | Make, test and establish the validity of conjectures about geometric properties and relationships using counterexample, inductive and deductive reasoning, and paragraph or two-column proof, including:
a. prove the Pythagorean Theorem;
b. prove theorems involving triangle similarity and congruence;
c. prove theorems involving properties of lines, angles, triangles and quadrilaterals; and
d. test a conjecture using basic constructions made with a compass and straightedge or technology. (ORC Resources) | | 4. | Construct right triangles, equilateral triangles, parallelograms, trapezoids, rectangles, rhombuses, squares and kites, using compass and straightedge or dynamic geometry software. (ORC Resources) | | 5. | Construct congruent or similar figures using tools, such as compass, straightedge, and protractor or dynamic geometry software. (ORC Resources) | | 6. | Identify the reflection and rotation symmetries of two- and three-dimensional figures. (ORC Resources) | | 7. | Perform reflections and rotations using compass and straightedge constructions and dynamic geometry software. (ORC Resources) | | 8. | Derive coordinate rules for translations, reflections and rotations of geometric figures in the coordinate plane. (ORC Resources) | | 9. | Show and describe the results of combinations of translations, reflections and rotations (compositions); e.g., perform compositions and specify the result of a composition as the outcome of a single motion, when applicable. (ORC Resources) | | 10. | Solve problems involving chords, radii, and arcs within the same circle. (ORC Resources) |
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