MAT-08.G

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Geometry

  • Understand congruence and similarity using physical models, transparencies, or geometry software. 
  • Understand and apply the Pythagorean Theorem.
  • Solve real-world and mathematical problems involving volume of cylinders, cones, and spheres.

Domain Description

Students use ideas about distance and angles, how they behave under translations, rotations, reflections, and dilations, and ideas about congruence and similarity to describe and analyze two-dimensional figures and to solve problems. Students show that the sum of the angles in a triangle is the angle formed by a straight line, and that various configurations of lines give rise to similar triangles because of the angles created when a transversal cuts parallel lines. Students understand the statement of the Pythagorean Theorem and its converse, and can explain why the Pythagorean Theorem holds, for example, by decomposing a square in two different ways. They apply the Pythagorean Theorem to find distances between points on the coordinate plane, to find lengths, and to analyze polygons. Students complete their work on volume by solving problems involving cones, cylinders, and spheres.

Standards in this Domain

  • MAT-08.G.01 - Verify experimentally the properties of rotations, reflections, and translations
  • MAT-08.G.02 - Understand that a two-dimensional figure is congruent to another if the second can be obtained from the first by a sequence of rotations, reflections, and translations; given two congruent figures, describe a sequence that exhibits the congruence between them.
  • MAT-08.G.03 - Describe the effect of dilations, translations, rotations, and reflections on two-dimensional figures using coordinates.
  • MAT-08.G.04 - Understand that a two-dimensional figure is similar to another if the second can be obtained from the first by a sequence of rotations, reflections, translations, and dilations; given two similar two-dimensional figures, describe a sequence that exhibits the similarity between them.
  • MAT-08.G.05 - Use informal arguments to establish facts about the angle sum and exterior angle of triangles, about the angles created when parallel lines are cut by a transversal, and the angle-angle criterion for similarity of triangles. For example, arrange three copies of the same triangle so that the sum of the three angles appears to form a line, and give an argument in terms of transversals why this is so.
  • MAT-08.G.06 - Explain a proof of the Pythagorean Theorem and its converse.
  • MAT-08.G.07 - Apply the Pythagorean Theorem to determine unknown side lengths in right triangles in real-world and mathematical problems in two and three dimensions.
  • MAT-08.G.08 - Apply the Pythagorean Theorem to find the distance between two points in a coordinate system.
  • MAT-08.G.09 - Know the formulas for the volumes of cones, cylinders, and spheres and use them to solve real-world and mathematical problems.

Calculation Method for Domains

Domains are larger groups of related standards. The Domain Grade is a calculation of all the related standards. Click on the standard name below each Domain to access the learning targets and rubrics/ proficiency scales for individual standards within the domain.

» Eighth Grade Math