Vocabulary for the Common Core Sixth Grade
base: The side of a polygon that is perpendicular to the altitude or height. Base of this triangle Height
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.
The Cartesian coordinate plane is named for a French mathematician, René Descartes, who was the first to link geometry to algebra.
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.)
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.
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.
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.
Compose: to put together, as in numbers or shapes. The two right triangles compose a rectangle.
Cube: A rectangular solid having six congruent square faces.
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.
Decompose: To separate into components or basic elements. The trapezoid can be turned into three identical triangles.
Edge: the intersection of faces in a three- dimensional figure.
Face: a flat surface of a three- dimensional figure.
Height: the perpendicular distance from a vertex to the opposite side of a plane figure. Height or altitude of the trapezoid
Length: distance from one point to another
Net: A 2-dimensional shape that can be folded into a 3-dimensional figure is a net of that figure. (Also called a network.)
Origin: The intersection of the x- and y-axes in a coordinate plane, described by the ordered pair (0, 0).
Perpendicular: lines that cross at a right angle
Polygon: A closed figure formed from line segments that meet only at their endpoints.
Polyhedron: a geometric solid in three dimensions with flat faces and straight edges (plural polyhedra or polyhedrons)
Prism: The traditional geometrical shape is that of a triangular prism with a triangular base and rectangular sides
Prism: a 3-dimensional figure that has two congruent and parallel faces that are polygons. The remaining faces are parallelograms.
Pyramid:A polyhedron whose base is a polygon and whose other faces are triangles that share a common vertex.
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 (+,-)
Rectangle: a quadrilateral with two pairs of congruent, parallel sides and four right angles.
rectangular prism: A prism with six rectangular faces where the lateral edge is perpendicular to the plane of the base.
right triangle: A triangle that has one 90º angle.
special quadrilaterals: four-sided figures which have a name for their type of figure
surface area: the total area of the faces (including the bases) and curved surfaces of a solid figure.
three- dimensional: 3- D. Existing in 3 dimensions; having length, width, and height.
triangular prism: A prism with three rectangular faces and two triangular bases where the lateral edge is perpendicular to the plane of the base.
vertex, vertices: The point at which two line segments, lines, or rays meet to form an angle. (plural – vertices) Vertex
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
Width: the distance across a figure or object The red double- ended arrow shows the width.
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.