# Geometry Final

dmr1001's version from 2017-05-01 18:41

## Section 1

central anglean angle with its vertex at the center of the circle
minor arcmeasure of the central angle
semi circlemeasure = 180
chorda line segment that joins 2 points on the circumference of a circle
diameterchord that passes through the center of a circle
inscribed angleformed by 2 chords that meet on the same point in a circle
tangentline in the plane of a circle that touches circle in exactly one point. point of tangency
secantline that contains a chord
sectora region bounded by 2 radii and an arc of the circle
isometrya transformation of a geometric figure that preserves length and angle measure of the figure and its image under the transformation

## Section 2

rotationone point is fixed and the image points are transformed to a negative position
reflectiontransformed as a mirror image
translationeach point is moved the same distance in the same direction from the original point
glide reflectionthe product of a reflection and then a translation
tessellationcreated when a shape is continuously repeated on a plane without any gaps or overlaps
eschertessellations = tiling
pure tessellationcreated using only one shape
semi pure tessellationinvolves more than one type of polygon
semiregular tessellationformed by 2 or more regular polygons. the arrangement of polygons at every vertex point is identical
diametera line segment that passes through the center of a circle and whose endpoint lie on the circle

## Section 3

locusset of points that forms a geometric figure or graph
circumference of a circledistance around circle. 2*pie*r
area of a circleamount of space occupied by the circle pie*r^2
circumscribeto enclose or draw a ling around an object
inscribean object that is enclosed within a geometric figure
central angleangle formed by 2 radii drawn to consecutive vertices
apothemthe perpendicular distance from the center of the polygon to a side
area of a regular polygonhalf the product of the apothem and the perimeter
equation of a circle(x-h)^2 + (y-k)^2 = r^2 h and k are the x and y of the center of the circle
mediansegment from a vertex to the midpoint of the opposite side
centroidwhere the 3 medians intersect
altitudethe perpendicular segment from a vertex to the line that contains the opposite side
orthocenterthe point where all 3 altitudes of the triangle intersect

## Section 4

perpendicular bisectorsa line that is perpendicular to the segment at its midpoints
circumcenterthe point where the perpendicular bisectors intersect
transveralstwo lines intersected by a third
polyhedron3D geometric figure whose sides are polygons
facea flat surface of a polyhedron
edgethe intersection of the faces in a polyhedron
lateral facethe face that joins the bases of a polyhedron
vertexa point where 2 or more straight lines meet
apexthe highest point in the polyhedron
prismsa solid figure whose bases are congruent and parallel to one another and whose sides are parallelograms