The point on the line segment that is the same distance from both endpoints. The midpoint bisects the segment.

Back

Centroid

Front

The point of concurrency of a triangle's three medians.

Back

Coplanar

Front

In the same plane.

Back

Decagon

Front

Ten sided polygon.

Back

Pentagon

Front

A five sided polygon.

Back

Line

Front

An undefined term thought of as a straight,
continuous arrangement of infinitely many points
extending forever in two directions. A line has
length, but no width or thickness, so it is
one-dimensional.

Back

Hexagon

Front

A six sided polygon

Back

Nonagon

Front

Nine sided polygon.

Back

Ray

Front

A point on a line, and all the points of the line that lie on one side of this point.

Back

Perpendicular (lines, line segments, or rays)

Front

Lines are perpendicular if they meet at 90 degree angles. Lines segments and rays are perpendicular if they lie on perpendicular lines.

Back

n-th Term

Front

The number that a function rule generates as output for a counting number n.

Back

Hypotenuse

Front

The side opposite the right angle in a right triangle. It is the longest side of a triangle.

Back

Scalene Triangle

Front

Triangle that all sides and all angles are different

Back

Regular

Front

All sides are equal and all angles are equal within a polygon

Back

Plane

Front

An undefined term thought of as a flat surface that extends infinitely along its edges. This has length and width but no thickness, so it is two- dimensional.

Back

Bisect

Front

To divid into two congruent parts.

Back

Dodecagon

Front

12 sided polygon.

Back

Converse

Front

The statement formed by exchanging the antecedent and the consequent of a conditional statement.

Back

Concave polygon

Front

A polygon with at least one diagonal outside the polygon.

Back

Cosine

Front

The ratio of the length of the leg adjacent to the angle to the length of the hypotenuse

Back

Center

Front

The coplanar point from which all points of the circle are the same distance.

Back

Secant Line

Front

A line that intersects a circle or sphere in two points.

Back

Sine

Front

The ratio of the length of the leg opposite the angle to the length of the hypotenuse

Back

Convex polygon

Front

A polygon with no diagonal outside the polygon.

Back

Vertex

Front

A point of intersection of two or more rays or line segments in a geometric figure. The plural of vertex is vertices.

Back

Acute Triangle

Front

Triangle with all angles less than 90°

Back

Segment

Front

Two points and all the points between them that are collinear with the two points. To measure this, you measure the length.

Back

Angle

Front

Two noncollinear rays having a common endpoint.

Back

Conjecture

Front

A generalization resulting from inductive reasoning.

Back

Triangle

Front

Polygon with three sides

Back

Contrapositive

Front

The statement formed by exchanging and negating the antecedent and the consequent of a conditional statement

Back

Endpoint

Front

The point at either end of a segment or an arc, or the first point of a ray.

Back

Equiangular

Front

Equal angles

Back

Intersecting lines

Front

Two lines that cross each other

Back

Skew lines

Front

Lines that are not in the same plane and do not intersect.

Back

Incenter

Front

The point of concurrency of a triangle's three angle bisectors.

Back

Parallelogram

Front

A quadrilateral with two pairs of parallel sides

Back

Collinear

Front

On the same line.

Back

Orthocenter

Front

The point of concurrency of a triangle's three altitudes (or of the lines containing the altitudes).

Back

Non-collinear

Front

Not on the same line.

Back

Pythagorean Tripple

Front

Three positive integers with the property that the sum of the squares of two of the integers equals the square of the third.

Back

Point

Front

An undefined term thought of as a location with no size or dimension. It is the most basic building block of geometry. In a two dimensional coordinate system, a point's location is represented by an ordered pair of numbers (x,y).

Back

Median

Front

A line segment connecting a vertex of a triangle to the midpoint of the opposite side.

Back

Altitude

Front

A perpendicular segment from a vertex to the base or to the line or plane containing the base.

Back

Circumcenter

Front

The point of concurrency of a triangle's three perpendicular bisectors.

Back

Center of gravity

Front

A point from which the weight of a body or system may be considered to act. In uniform gravity it is the same as the center of mass.

Back

Diagonal

Front

A line segment connecting two non consecutive vertices of a polygon or polyhedron.

Back

Space

Front

An undefined term thought of as the set of all points. This extends infinitely in all directions, so it is three-dimensional.

Back

Equilateral

Front

Equal sides

Back

Section 2

(50 cards)

Cone

Front

A solid or hollow object that tapers from a circular or roughly circular base to a point.

Back

Obtuse Triangle

Front

A triangle with an angle greater than 90 degrees

Back

Central Angle

Front

A central angle is an angle whose vertex is the center O of a circle and whose legs (sides) are radii intersecting the circle in two distinct points A and B thereby subtending an arc between those two points whose angle is (by definition) equal to that of the central angle itself.

Back

Slope Formula

Front

In a two-dimensional coordinate system,
the ratio of the vertical change to the horizontal
change between two points on a line.
Formula: slope: (y2-y1)/(x2-x1)

Back

Adjacent leg (of an acute angle in a right triangle)

Front

The side of the angle that is not the hypotenuse.

Back

Face

Front

a flat surface of a three-dimensional figure.

Back

Semicircle

Front

a half of a circle or of its circumference

Back

Surface area

Front

The total area of the surface of a three-dimensional object.

Back

Inductive Reasoning

Front

The process of observing
data, recognizing patterns, and making
generalizations about those patterns.

Back

Compass

Front

A technical drawing tool that can be used for transcribing circles or arcs.

Back

Straightedge

Front

A straightedge is a tool with an edge free from curves, or straight, used for transcribing straight lines, or checking the straightness of lines. If it has equally spaced markings along its length it is usually called a ruler.

Back

Midpoint Formula

Front

The point on the line segment that is the same
distance from both endpoints. The midpoint
bisects the segment.
Fromula:[(x1 + x2)/2 , (y1 + y2)/2]

Back

Transversal

Front

A line that cuts across two or more (usually parallel) lines

Back

Opposite leg (of an acute angle in a right triangle)

Front

The side of the triangle that is not a side of the angle.

Back

Area

Front

The measure of the size of the interior of a figure,expressed in square units.

Back

Supplementary Angles

Front

Angles that add to 180 degrees.

Back

Right Triangle

Front

A triangle with a right angle

Back

Isosceles Triangle

Front

A triangle that has two sides the same length

Back

Cylinder

Front

A solid object with:
• two identical flat ends that are circular or elliptical
• and one curved side.

Back

Arc

Front

An arc (symbol: ⌒) is a closed segment of a differentiable curve. A common example in the plane (a two-dimensional manifold), is a segment of a circle called a circular arc.

Back

Corresponding Angles

Front

The angles in matching corners that are created when two lines are crossed by another line (which is called the Transversal).

Back

Concentric Circles

Front

Circles that share the same center.

Back

Cube

Front

A symmetrical three-dimensional shape, either solid or hollow, contained by six equal squares.

Back

Consecutive (angles, sides, or vertices of a polygon)

Front

Two angles that share a common side, two sides that share a common vertex, or two vertices that are the endpoints of one side. Consecutive sides are also called adjacent sides.

Back

Obtuse angle

Front

An angle that measures more than 90 degrees but less than 180 degrees.

Back

Bilateral Symmetry

Front

Body plan in which only a single, imaginary line can divide the body into two equal halves.

Back

Undefined term

Front

In geometry, definitions are formed using known words or terms to describe a new word. There are three words in geometry that are not formally defined. These three undefined terms are point, line and plane.

Back

Tangent Line of a Circle

Front

A line which touches a circle or ellipse at just one point

Back

Radius

Front

A line segment from the center of a circle or sphere to a point on the circle or sphere. Also, the length of that line segment.

Back

Perimeter

Front

The length of the boundary of a two dimensional figure. For a polygon, it is the sum of the lengths of its sides.

Back

Minor Arc

Front

An arc of a circle that is less than a semicircle

Back

Sphere

Front

A round solid figure, or its surface, with every point on its surface equidistant from its center.

Back

Concurrent lines

Front

Three or more lines in a plane (or higher-dimensional space)are said to be concurrent if they intersect at a single point.

Back

Counter Example

Front

An example which disproves a proposition

Back

Distance formula

Front

The distance between (x1,y1) and (x2,y2) is equal to square root of (x1-x2) ^2 +(y1-y2)^2

Back

Solid

Front

A 3 dimensional shape .

Back

Tangent

Front

to a plane curve at a given point is the straight line that "just touches" the curve at that point.

Back

Major Arc

Front

An arc of a circle that is greater that a semicircle.

Back

Right angle

Front

An angle of 90°

Back

Edge

Front

the intersection of faces in a three-dimensional figure.

Back

Inscribed

Front

Having each vertex on the circle, such as a
triangle inscribed in a circle.

Back

Base

Front

In a polygon: A side of polygon used from reference to determine an altitude or other feature.
In a solid: A polygon or circle used for
reference to determine an altitude or other feature
of the solid, or to classify the solid.

Back

Adjacent Angles

Front

Angles that have a common side and a common vertex .

Back

Pythagorean theorem

Front

The relationship among the lengths of the sides of a right triangle that the sum of the squares of the lengths equals the square of the length of the hypotenuse.

Back

Acute angle

Front

An angle smaller than a right angle (less than 90°).

Back

Point of Tangency

Front

The point of intersection of a tangent line and a circle.

Back

Complementary Angles

Front

Two angles whose sum is 90 degrees.

Back

Conditional statement

Front

(Symbolized by p-->q) Is an if-then statement in which p is a hypothesis and q is a conclusion.

Back

Biconditional Statement

Front

When a conditional statement and its converse are both true.

Back

Diameter

Front

A chord of a circle that contains the center, or the length of that chord.

Back

Section 3

(20 cards)

Protractor

Front

An instrument for measuring angles, typically in the form of a flat semicircle marked with degrees along the curved edge.

Back

Alternative Exterior Angles

Front

A pair of angles, formed by a transversal intersecting two lines that lie between the two lines and are on opposite sides of the transversal.

Back

Rhombus

Front

A parallelogram with 4 congruent sides.

Back

Kite

Front

A quadrilateral that has two pairs of consecutive congruent sides, but opposite sides are not congruent.

Back

Congruent

Front

Identical in shape and size.

Back

Circumference

Front

The perimeter of a circle, which is
the distance around the circle. Also, the curved
path of the circle itself.

Back

N-gon

Front

A polygon with n sides.

Back

Pyramid

Front

An object, shape, or arrangement in the form of a pyramid.

Back

Lateral Face

Front

Lateral face of a solid figure is the face of the solid. Its is on each side and does not include the base.

Back

Segment Bisector

Front

A line, ray, or segment that passes through the midpoint of a line segment in a plane.

Back

Alternative Interior Angles

Front

A pair of angles, formed by a transversal intersecting two lines that do not lie between the two lines and are on opposite sides of the transversal.

Back

Trapezoid

Front

A quadrilateral with exactly one pair of parallel sides

Back

Circumscribed

Front

Having all sides tangent to the circle, such as a
triangle circumscribed about a circle.

Back

Polyhedron

Front

A solid figure with many plane faces, typically more than six.

Back

Angle Bisector

Front

A ray that has its endpoint at the vertex of the angle and that divides the angle into two congruent angles.

Back

Slope of Line

Front

In a two-dimensional coordinate system, the ratio of the vertical change to the horizontal change between two points on a line.

Back

Rotational Symmetry

Front

an object that looks the same after a certain amount of rotation

Back

Circumference formula

Front

pi multiplied by the radius of circle the product then multiplied by two

Back

Line of Reflection

Front

The line of reflection is the perpendicular bisector of the segment joining every point and its image.

Back

Deductive Reasoning

Front

a logical process in which a conclusion is based on the concordance of multiple premises that are generally assumed to be true