Common Core State Standards for Mathematics Standards for Mathematical Practice [K-12] Make sense of problems and persevere in solving them. [K-12] Reason abstractly and quantitatively. [K-12] Construct viable arguments and critique the reasoning of others. [K-12] Geometry [K - 8] Identify and describe shapes (squares, circles, triangles, rectangles, hexagons, cubes, cones, cylinders, and spheres). [K] 1. Describe objects in the environment using names of shapes, and describe the relative positions of these objects using terms such as above, below, beside, in front of, behind, and next to. [K] 2. Correctly name shapes regardless of their orientations or overall size. [K] 3. Identify shapes as two-dimensional (lying in a plane, "flat") or three-dimensional ("solid"). [K] Analyze, compare, create, and compose shapes. [K] 4. Analyze and compare two- and three-dimensional shapes, in different sizes and orientations, using informal language to describe their similarities, differences, parts (e.g., number of sides and vertices/"corners") and other attributes (e.g., having sides of equal length). [K] 5. Model shapes in the world by building shapes from components (e.g., sticks and clay balls) and drawing shapes. [K] 6. Compose simple shapes to form larger shapes. For example, "Can you join these two triangles with full sides touching to make a rectangle?" [K] Reason with shapes and their attributes. [1 - 3] 2. Compose two-dimensional shapes (rectangles, squares, trapezoids, triangles, half-circles, and quarter-circles) or three-dimensional shapes (cubes, right rectangular prisms, right circular cones, and right circular cylinders) to create a composite shape, and compose new shapes from the composite shape.  1. Recognize and draw shapes having specified attributes, such as a given number of angles or a given number of equal faces. Identify triangles, quadrilaterals, pentagons, hexagons, and cubes.