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## Ignore words

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perimeter
The distance around a geometric figure.
Base (of a polygon)
the length of one side of a polygon
Height (of a polygon)
the length of the altitude of a figure (perpendicular height)
area
the surface; Length x Width
composite figure
a figure made up of two or more figures
Apothem
The perpendicular distance from the center to a side of a regular polygon.
polygon
a closed figure made by joining line segments where each line segment intersects exactly 2 others
regular polygon
a convex polygon in which all sides and angles are congruent
convex
a figure in which all the diagonals are contained inside the polygon
concave
a figure in which at least one diagonal is outside the polygon
pentagon
a 5 sided polygon
hexagon
a 6-sided polygon
heptagon
a 7-sided polygon
octagon
an 8-sided polygon
nonagon
a 9-sided polygon
decagon
a 10-sided polygon
Dodecagon
a 12-sided polygon
n-gon
a polygon with "n" sides
Polyhedra
3-dimentional solids whose faces are polygons are joined at their edges
net
a 2-dimentional pattern that can be folded to make a 3-dimentional solid
Area of a Rectangle Theorem
the product of its base and height
Area of a Parallelogram Theorem
the product of a base and the corresponding height
Area of a Triangle Theorem
half the product of the base and the corresponding height
base of a triangle
any of the sides of a triangle
corresponding height
the length of the altitude to a line containing the stated base
Area of a Trapezoid Theorem
half the product of the height and the sum of the bases
Height of a Trapezoid
the perpendicular distance between the bases
Area of a Rhombus Theorem
half the product of the lengths of the diagonals
Area of a Kite Theorem
half the product of the lengths of the diagonals
the distance from the center to a vertex
center of the polygon
center of the circumscribed circle of the polygon
Congruent Polygon Theorem
If two figures are congruent,then their areas are equal
Area of a Regular Polygon Theorem
half the product of the apothem and the perimeter
Perimeters and Areas of Similar Figures Theorem
If the scale factor of two similar figures is a ÷ b, then
Area of a Triangle Given SAS Theorem
half the product of the lengths of two sides and the sine of the included angle
Circle
in a plane, the set of all points equidistant from a given point
center of the circle
the point that is equidistant from all the points on the circle in a plane
diameter of a circle
Goes across the circle
a segment that has one endpoint at the center of a circle and the other endpoint on the same circle
congruent circles
Central Angle
an angle whose vertex is the center of the circle
arc
part of a circle
semicircle
half of a circle
minor arc
smaller than a semicircle; named by its endpoint with an arc symbol over the letters - ⌒
major arc
larger than a semicircle; named by its endpoints and another point between the endpoints on the arc with an arc symbol over the letters - ⌒
minor arc measure
equal to the measure of the corresponding central angle
major arc measure
equal to the difference between 360° and the measure of the related minor arc
arcs of the same circle that have exactly one point in common
the measure of the arc formed by two adjacent arcs is the sum of the measures of the two arcs
Circumference of a Circle
π times the diameter
Circumference
2πr
π
irrational number, pi; the ratio of the circumference of a circle to its diameter
concentric circles
coplanar circles that have the same center
arc length
a fraction of the circumference
Arc Length Theorem
the product of the ratio of the measure of the arc to 360° and the circumference of the circle
Area of a Circle Theorem
the product of π and the square of the radius
Area of a Sector of a Circle Theorem
the product of the ratio of the measure of the arc to 360° and the area of the circle
Sector of a Circle
region bounded by an arc of the circle and the two radii to the arc's endpoints; names using one arc endpoint, the center of the circle, and the other arc endpoint
area of a sector
a fractional part of the area of a circle
segment of a circle
part of a circle bounded by an arc and the segment joining its endpoints
Area of Segment
is equal to the difference of the area of a sector and the area of triangle formed bounded by the segment of the circle and the center of the circle
geometric probability
a ratio that involves geometric measures such as length or area;
geometric probability of an event
P(event) = (number of favorable outcomes) ÷ (number of possible outcomes)