Geometry Vocab Semester 2

Question 1

Dilation

Answer 1

a transformation determined by a scale factor

Question 2

Enlargement

Answer 2

an image that is larger than the original image

Question 3

Proportion

Answer 3

an equation of the form a/b=c /d that states that two ratios are equal

Question 4

Ratio

Answer 4

a comparison of 2 quantities using division

Question 5

Reduction

Answer 5

an image that is smaller than the original image

Question 6

Scale Factor

Answer 6

the ratio of the lengths of 2 corresponding sides of 2 similar polygons

Question 7

Similar polygons

Answer 7

polygons that have the exact same shape but not necessarily the same size

Question 8

cosine

Answer 8

the ratio of the measure of the leg adjacent to the angle to the measure of the hypotenuse

Question 9

geometric mean

Answer 9

the positive square root of the product of 2 numbers

Question 10

sine

Answer 10

the ratio of the measure of the leg opposite the angle to the measure of the hypotenuse

Question 11

tangent

Answer 11

the ratio of the measure of the leg opposite the angle to the measure of the hypotenuse

Question 12

trigonometry

Answer 12

the study of the properties of triangles and triangle measurements

Question 13

arc

Answer 13

a part of a circle that is defined by 2 endpoints

Question 14

central angle

Answer 14

an angle that intersects a circle in 2 points and has its vertex at the center of the circle

Question 15

chord

Answer 15

a segment with endpoints that are on the circle

Question 16

circle

Answer 16

all the points in a plane equidistant from a given point called the center

Question 17

circumference

Answer 17

the distance around a circle

Question 18

circumscribed about a polygon

Answer 18

a circle that contains all the vertices of the polygon

Question 19

concentric circles

Answer 19

coplanar circles with the same center

Question 20

diameter

Answer 20

a chord that passes through the center of a circle

Question 21

inscribed angle

Answer 21

an angle that has a vertex on a circle and sides that contain chords of the circle

Question 22

major arc

Answer 22

an arc with a measure greater than 180 degrees

Question 23

minor arc

Answer 23

an arc with a measure less than 180 degrees

Question 24

pi

Answer 24

an irrational number represented by the ratio of the circumference of a circle to the diameter of the circle

Question 25

radius

Answer 25

an segment whose endpoints are the center of a circle and a point on the circle

Question 26

secant

Answer 26

any line that intersects a circle in exactly 2 points

Question 27

semicircle

Answer 27

an arc that measures 180 degrees

Question 28

tangent line

Answer 28

a line that intersects a circle in exactly one point

Question 29

sector

Answer 29

the region of a circle bounded by a central angle and its intercepted arc

Question 30

apothem of a polygon

Answer 30

a segment that is drawn from the center of a regular polygon perpendicular to a side of the polygon

Question 31

lateral area

Answer 31

the area (not including the bases) of prisms, pyramids, cylinders, and cones

Question 32

surface area

Answer 32

the sum of the area of all faces of 3-dimensional figures

Question 33

cone

Answer 33

a solid with a circular base, a vertex not contained in the same plane as the base, and a lateral surface area composed of all points in the segments connecting the vertex to the edge of the base

Question 34

cylinder

Answer 34

a figure with bases that are formed by congruent circles in parallel planes

Question 35

sphere

Answer 35

all the points in space that are equidistant from a given point are called the center

Question 36

prism

Answer 36

a solid formed by congruent polygonal bases and lateral faces that are parallelograms

Question 37

pyramid

Answer 37

a solid formed by a polygonal base and triangular faces that meet at a point called the vertex