1. Vocabulary for the Common Core Sixth Grade

2.  base: The side of a polygon that is perpendicular to the altitude or height. Base of this triangle Height

3.  Cartesian coordinate plane: also known as coordinate plane. A horizontal axis crosses a vertical axis, making it possible to identify points on the plane by two numbers.

4.  The Cartesian coordinate plane is named for a French mathematician, René Descartes, who was the first to link geometry to algebra.

5.  The coordinate plane is a two- dimensional system in which the coordinates of a point are its distances from two intersecting, usually perpendicular, straight lines called axes. (Also called coordinate grid or coordinate system.)

6.  x-axis, x-coordinate: on the coordinate plane, the horizontal axis is the x-axis. A number on that axis is called the x-coordinate. The x-axis in this picture is yellow.

7.  y-axis, y-coordinate: on the coordinate plane, the vertical axis is the y-axis. A number on that axis is called the y- coordinate. The y-axis is green in this picture.

8.  Coordinate: one of the two numbers used to identify a point on the coordinate plane. Four examples are on the grid next to this text.

9.  Compose: to put together, as in numbers or shapes. The two right triangles compose a rectangle.

10.  Cube: A rectangular solid having six congruent square faces.

11.  cubic units: Volume is measured in "cubic" units. The volume of a figure is the number of cubes required to fill it completely, like blocks in a box.

12.  Decompose: To separate into components or basic elements. The trapezoid can be turned into three identical triangles.

13.  Edge: the intersection of faces in a three- dimensional figure.

14.  Face: a flat surface of a three- dimensional figure.

15.  Height: the perpendicular distance from a vertex to the opposite side of a plane figure. Height or altitude of the trapezoid

16.  Length: distance from one point to another

17.  Net: A 2-dimensional shape that can be folded into a 3-dimensional figure is a net of that figure. (Also called a network.)

18.  Origin: The intersection of the x- and y-axes in a coordinate plane, described by the ordered pair (0, 0).

19.  Perpendicular: lines that cross at a right angle

20.  Polygon: A closed figure formed from line segments that meet only at their endpoints.

21.  Polyhedron: a geometric solid in three dimensions with flat faces and straight edges (plural polyhedra or polyhedrons)

22.  Prism: The traditional geometrical shape is that of a triangular prism with a triangular base and rectangular sides

23.  Prism: a 3-dimensional figure that has two congruent and parallel faces that are polygons. The remaining faces are parallelograms.

24.  Pyramid:A polyhedron whose base is a polygon and whose other faces are triangles that share a common vertex.

25.  Quadrant I, Quadrant II, Quadrant III, Quadrant IV: the four parts of the coordinate grid as marked in the diagram; Quadrant I is (+,+) Quadrant II is (-,+) Quadrant III is (-,-) Quadrant IV is (+,-)

26.  Rectangle: a quadrilateral with two pairs of congruent, parallel sides and four right angles. 

27.  rectangular prism: A prism with six rectangular faces where the lateral edge is perpendicular to the plane of the base. 

28.  right triangle: A triangle that has one 90º angle.

29.  special quadrilaterals: four-sided figures which have a name for their type of figure

30.  surface area: the total area of the faces (including the bases) and curved surfaces of a solid figure.

32.  three- dimensional: 3- D. Existing in 3 dimensions; having length, width, and height.

34.  triangular prism: A prism with three rectangular faces and two triangular bases where the lateral edge is perpendicular to the plane of the base.

35.  vertex, vertices: The point at which two line segments, lines, or rays meet to form an angle. (plural – vertices) Vertex

36.  Volume: The number of cubic units it takes to fill a figure. It takes 27 cubes to fill this box: 3 x 3 x 3 = 27

37.  Width: the distance across a figure or object The red double- ended arrow shows the width.

39.  fraction edge length: the length of the edge of a geometric figure which does not measure in whole number units. The length of this side is 2 ½ units.