ENGINEERING MATH TERMS

An annulus is a plane figure which is composed of two concentric circles. The area of the annulus can be calculated by getting the difference between the area of the larger circle and the area of the smaller circle. Also, its area can be calculated by removing the hole. This method is called

Law of extremities

Each of the faces of a regular hexahedron is a

Square

It is a polyhedron of which two faces are equal polygons in parallel planes and the other faces are parallelogram.

Prism

The apothem of a polygon is __________ of its inscribed circle.

Radius

Each angle of regular dodecagon is equal to

150

The area bounded by two concentric circles is called

Annulus

One-fourth of a great circle is called

Quadrant

Points that lie on the same plane are called

Coplanar

The volume of the cicular cylinder is equal to the product of its base and altitude.

Theorem

The study of properties of figures in three dimensions.

Solid geometry

A plane closed curve, all points of which are the same distance from a point within, called the center

Circle

What is the angle of π and less than 2π?

Oblique angle

What is the value in degress of 1 radian?

57.3°

Bases

Prism are named according to their __________.

In plane geometry, two circular arcs that are together make up a full circle are called

Conjugate arcs

Polygons are classified according to their number of __________.

Sides

When two planes intersects with each other, the amount of divergence between the two planes is expressed by measuring the

Dihedral angle

An angular unit equivalent to 1/4000 of the circumference of a circle is called

Grad

Express 45° in mils.

800

The arc length equal to the radius of the circle is called

Radian

A five-pointed star is also known as

Pentagram

If two or more lines have a single point which lies on all of them, then they are

Concurrent

Superposition

The action of bringing on geometric figure into coincidence with another is called

A line that intersect two or more lines at distinct points.

Transversal

An arc length equal to the radius of a circle.

Radian

An angle which is 1/400th of the full revolution.

Gon

Another term for gon.

A and C

An angle whose vertex is a point on the circle and whose sides are chords is known as

Inscribed angle

An angle greater than the right angle but less than a straight angle.

Obtuse angle

Any angle greater than a straight angle but less than two straight angles is known as __________ angle.

Reflex

The angle formed by the prolongation of one side and the adjacent side of the polygon.

Exterior angle

Two angles which have the same vertex and the sides of one are form by extending the sides one are form by extending the sides of the other.

Vertical angles

Another term for exterior angle.

Deflection angle

What is the sum of all deflection angles in given polygon?

Always equal to 360°

The coterminal angle is 120° is

-240°

Two planes intersect each other. What is the term for the angle formed perpendicular to the intersection of two planes?

Dihedral angle

When a terminal side of an angle coinsides with an axis, the angle is a

Quadrantal angle

If the exterior angle of a polygon is obtuse, its corresponding interior angle is

An acute angle

The measure of 2.25 revolutions counterclockwise is

815°

Solid angles are measured in

Steradians

What is the largest measure (in steradians) of a solid angle

4π

Steradians measure in space in analog of __________ measured in the plane.

Radians

A part of a circle is called

Arc

It is the union of the chord of a circle and the intercepted arc.

Segment

A __________ of a circle in the figure bounded by two radii and the intercepted arc.

Sector

The apothem of a polygon is the __________ of its inscribed circle.

Radius

As the area of the circle increases, the ratio of its circumference to its diameter

Remains constant

A circle is said to be _________ to a polygon having the same perimeter with that of the circle.

Isoperimetric

Which of the following is NOT a property of a circle?

The arcs of two circles subtended by equal central angles are always equal.

All circles having the same center but of unequal radii are called

Concentric circles

Two chords of a circle which joins a point on the circle to the end points of a diameter and forms a right angle.

Supplementary chords

The center of the inscribed circle of a triangle is known as known as __________ of the triangle.

Incenter

Supplementary chords are two chords which join a point on the circle to the endpoints of a diameter. The supplemental chords subtend a/an __________ angle.

Right

A circle or radius R has a curvature of

1/R

A polygon is __________ when no side, when extended, will pass through the interior of the polygon.

Convex

A polygon is said to be a regular polygon if its is

All of the above

Polygon inscribed in the same circle called

Concyclic polygons

If n is the number of sides of a polygon, then the sum of all interior angles of a polygon is expressed as

(n-2) 180°

If n is the number of sides of a polygon, then the number of diagonals of a polygon is expressed as

(n/2) (n-3)

What do you call a polygon with 11 sides?

Undecagon

Pentagon is to 5 sides as __________ is to 11 sides.

Hendecagon

A polygon having 12 sides is called

Dodecagon

A polygon of 100 sides is called

Chilliagon

The highest point of a figure relative to a baseline or plane is called

Summit

Indicate the false statement.

Two angles are complementary if thier sum is equal to 180°.

Which of the following statements is correct?

All equilateral triangles are similar.

A quadrilateral with no sides parallel.

Trapezium

Which of the following BEST describes Ptolemy’s theorem?

It is used only for cyclic quadrilaterals.

The five-pointed star described by the diagonals of a regular pentagon.

Pentegram or penacle

The geometric figure remaining after a parallelogram has been removed from one corner of a larger similar polygon.

Gnomon

A oblique-angled parallelogram with for sides equal is called

All of the above

A non-convex quadrilateral with two pairs of adjacent equal sides is called

Deltroid

What is another term for parallelogram?

Rhomboid

Prisms are classified according to their

Bases

A solid cut of a given solid by two non parallel planes is called

Truncated prism

A polyhedron having bases two polygons in parallel planes and for lateral faces triangles or trapezoids with one side lying on the other base of the polygon.

Prismatoid

Portion of regular solid left after cutting of the upper part by a plane parallel to the base.

Frustum

Body or space bounded by surface every point of which is equidistant from a point within.

Sphere

A solid bounded by a zone and the planes of the zone’s base.

Spherical segment

The intersection of the sphere and the plane through the center is called

Great circle

The portion of a sphere enclosed between two great semi-circles having common end points, including the semi-circle.

Lune

A portion of the surface of a sphere included between two parallel planes.

Zone

If R is the radius of the sphere and h is the distance between two parallel plane, the area of the zone is

2πRh

The solid bounded by two great circles and the surface of a sphere is known as

Spherical wedge

A cone or cylinder with its top cut off by plane oblique to the base.

Ungula

A term given to cylinder with elliptical cross-section.

Cylindroid

A doughnut-like surface of revolution generated by rotating the circle through 360° in space about a line in its plane but now passing through the circle.

Torus

A regular solid star in a shape that is radiating from the center like rays of star.

Stellated star

Formed by intersection of rays from one point reflected or refracted from a curvature surface.

Caustic

The regular polyhedron is a solid with all its faces identical regular polygons. The regular polyhedrons are also known as

Platonic solids

There are how many regular polyhedra known to man?

5

An icosahedron is a regular polyhedron of __________ faces.

20

A regular polyhedron with 6 sides is called

Hexahedron

The face of a regular tetrahedron is a

Triangle

The face of a regular octahedron is a

Triangle

The face of a regular dodecahedron is a

Pentagon

The face of a regular icosahedron is a

Triangle

Which regular polyhedron does not have a face of a triangle?

Dodecahedron

How many edges are there in a dodecagon?

30

A tetrahedron has __________ vertices.

4