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