Glossary
 Acute Angle/Triangle

an angle/triangle with an angle smaller than 90°
 Allowance

the material needed for a specific component“We must allow this much extra”. Usually a seam for connection
 Apex

the intersection point of a cone, as seen in the elevation view
 Arc

a portion of a circumference
 Auxiliary Line

an extra element line added, different from the standard divisions
 Bisect

to divide in half
 Chord

a straight line from 2 points on a circumference
 Circumference

the distance around a circle, perimeter of a circle
 Diameter

the distance across a circle at center, twice the radius
 Elbow Rule

the number of pieces of a round elbow times 2 then minus 2(# of pcs x 22) gives us the number of gores in the elbow
 Element Line

a line representing an edge or bend
 Elevation View

looking at the front or side of something, to have elevation (height), 2D
 Frustum

a cone with the top cut parallel to the base
 Gore

a part of a round elbow which allows us to calculate the miter angle
 Horizontal

a line/plane level with the horizon. Flat, level
 Miter

an intersection of 2 pieces an irregular cut on the end of something
 Obtuse Angle/Triangle

an angle/triangle with an angle larger than 90°
 Parallel

a line/plane that is equal distance from another
 Pattern

the shape of the object, still in 2D form
 Perpendicular

a line/plane which is 90° to another
 Plan view

looking down at something, a “birds eye view”, “floor plan” (2D)
 Point of Tangency

a straight line that touches the circle at only one point
 Profile

a half of a plan view, drawn on the outside of an object
 Quadrant

a sector which equals one quarter of the area of a circle
 Radius

the distance from center to any point of the circumference, half the diameter
 Right Angle/Triangle

an angle/triangle which has a 90° angle
 Sector

the area of a circle bound by 2 radii and an arc
 Segment

the area of a circle bound by an arc and a chord
 Slant Height (small or large)

the hypotenuse of a cone, outside edge. The slant height is always a true length in the elevation view
 Stretchout

a shape which has been “stretched out”, to take a perimeter and make it straight
 StretchOut Angle/Arc

the angle or arc which encompasses a radial line pattern
 Tangent

a line which touches only 1 point of a circumference
 Triangulation from Plan View

the length of an element line, set 90° to the vertical height, gives the true length of that line
 True Length

a dimension or line that is not distorted by the view
 True Length Diagram (TLD)

a 90° corner in that we use to find the actual length of a line
 Vertex

the point at which an angle is formed
 Vertical

a line/plane straight up and down, vertically level (plumb)