Geometric photo
By: Mary byrd
Base of triangle
The side of a triangle which is perpendicular to
the altitude.
box
A box shape in three dimensional space.
Formally, a polyhedron for which
all faces are rectangles.
cevian
A line segment, ray, or line that extends from
a vertex of a triangle to the
opposite side (which may be
extended). Medians, altitudes, and angle
bisectors are all examples of cevians.
cosine
The trig function cosine, which is written cos θ.
For acute angles, cos θ can be found by
theSOHCAHTOA definition, shown below on
the left. The circle definition, a generalization
of SOHCAHTOA, is shown below on the
right. f(x) = cos x is a periodic
function with period 2π
Circle
The locus of all points that are a fixed distance
from a given point.
cuboids
A box shape in three dimensional space.
Formally, a polyhedron for which
all faces are rectangles.
cylinder
A three-dimensional geometric
figure with parallel congruent bases. The bases
can be shaped like any closed plane figure (not
necessarily a circle) and must be oriented
identically.
Note: The word cylinder often refers to a right
circular cylinder.
decagon
A polygon with ten sides
Diagonal of a polygon
A line segment connecting non-adjacent vertices of
a polygon. Note: An n-gon has diagonals.
dodecagon
A polygon with 12 sides.
hypotenuse
The side of a right triangle opposite the right
angle. Note: The hypotenuse is the longest
side of a right triangle.
Major arc
The longer of the two arcs between
two points on a circle.
octagon
A polygon with eight sides.
rectangle
A box shape on a plane. Formally, a rectangle is
a quadrilateral with four congruent angles (all
90°).
Rectangle parallelepiped
A box shape in three dimensional space.
Formally, a polyhedron for which
all faces are rectangles
Square pyramid
A nonnegative number that must be multiplied times itself to
equal a given number. The square root of xis written or x . For
example, since 3 = 9.
Note: never refers to a negative number. Even though (–3)(–
3) = 9, we do not say that –3 is a value of . Also, if x itself is
negative then is imaginary.
½
2
traoziod
Commentary: Under US definition
1, a parallelogram is a type of
trapezoid. Under US definition 2, a
parallelogram is not a type of
trapezoid. Regardless of which
definition you prefer, the trapezoid
area formula can be used to find
the area of a parallelogram.
Trapezoid
US usage, definition 1: A quadrilateral which
has a pair of opposite sides which are parallel.
The parallel sides are called the bases, and the
other two sides are called the legs.
US usage, definition 2: A quadrilateral which
has one parallel pair of opposite sides and one
non-parallel pair of opposite sides. The parallel
sides are called the bases, and the other two
sides are called the legs.
UK usage: The same as the US word trapezium.
The UK word trapezium means the same as the
US word trapezoid, and vice-versa.
trapezium
US usage: A quadrilateral with
no parallel sides.
UK usage: The same as the US word trapezoid.
The UK word trapezoid means the same as the
US word trapezium, and vice-versa.
Truncated cone
A cone or pyramid which has its apex cut off by
an intersecting plane. The plane may be
either obliqueor parallel to the base.
Note: If the truncating plane is parallel to the
base the figure is called a frustum
Truncated cylinder
A cylinder or prism which has one base cut off
by an intersecting plane. The other base is
unaffected by the truncation. The truncating
plane may be either oblique or parallel to the
bases