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

Quadrilateral

a four-sided polygon

Radius

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.