47 terms

# Lesson 2.1 Key Terms

PLTW - IED
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Acute Triangle
a triangle whose interior angles are all acute
Angle
the space between two lines or planes that intersect
Area
the extent of a 2-dimensional surface enclosed within a boundary
Axis
a straight line through a body or figure that satisfies certain conditions
Chamfer
two surfaces meeting at an angle different from 90 degrees
Circle
ellipse in which the two axes are of equal length
Circumscribe
to draw a geometric figure around another figure so that the two are in contact but do not intersect
Countersink
a hole (usually in wood) with the top part enlarged so that a screw or bolt will fit into it and lie below the surface
Counterbore
(1) A hole consisting of two depths so that the top of the head of an inserted bolt or screw will be flush with the outside surface. (2) A bit for enlarging the upper part of a hole.
Cylinder
a surface generated by rotating a parallel line around a fixed line
Diameter
the length of a straight line passing through the center of a circle and connecting two points on the circumference
Ellipse
A regular oval shape, traced by a point moving in a plane so that the sum of its distances from two other points is constant, or resulting when a cone is cut by an oblique plane which does not intersect the base.
Extrusion
A modeling process that creates a three-dimensional form by defining a closed two-dimensional shape and a length.
Inscribe
draw within a figure so as to touch in as many places as possible
Mass
a body of matter without definite shape
Origin
the point (0,0) where the x-axis and the y-axis intersect in a coordinate plane
Parallelogram
a quadrilateral whose opposite sides are both parallel and equal in length
Pattern
a customary way of operation or behavior
Pi
The numerical value of the ratio of the circumference of a circle to its diameter of approximately 3.14159.
Plane
a level of existence or development
Polygon
a closed plane figure bounded by straight sides
Prism
a polyhedron with two congruent and parallel faces (the bases) and whose lateral faces are parallelograms
a four-sided polygon
the length of a line segment between the center and circumference of a circle or sphere
Rectangle
a parallelogram with four right angles
Regular Polygon
a polygon with all sides and all angles equal
Revolution
a single complete turn (axial or orbital)
Right Triangle
a triangle with one right angle
Rotation
the act of rotating as if on an axis
Round
any circular or rotating mechanism
Solid
of definite shape and volume
Solid Modeling
A type of 3D CAD modeling that represents the volume of an object, not just its lines and surfaces. This allows for analysis of the object's mass properties.
Space
the unlimited expanse in which everything is located
Square
(geometry) a plane rectangle with four equal sides and four right angles
Surface Area
the extent of a 2-dimensional surface enclosed within a boundary
Tap
cut a female screw thread with a tap
Taper
the property possessed by a shape that narrows toward a point (as a wedge or cone)
Triangle
a three-sided polygon
Vertex
the point of intersection of lines or the point opposite the base of a figure
Volume
physical objects consisting of a number of pages bound together
Cartesian Coordinate System
a coordinate system for which the coordinates of a point are its distances from a set perpendicular lines that intersect at the origin of the system
Computer-Aided Design
Software that allows you to create engineering, architectural, and scientific designs
Geometric Constraint
Constant, non-numerical relationships between the parts of a geometric figure. Examples include parallelism, perpendicularity, and concentricity.
Numeric Constraint
A number value, or algebraic equation that is used to control the size or location of a geometric figure.
Obtuse Triangle
a triangle that contains an obtuse interior angle
Three-Dimensional
Having the dimensions of height, width, and depth.
Two-Dimensional
Having the dimensions of height and width, height and depth, or width and depth only.