Chapter 2

Question 0

Ray

Answer 0

The union of a half-line and its origin. It extends in only one direction
(2.1)

Question 1

Half-line

Answer 1

The set of all points on a line on a given side of a given point of the line
(2.1)

Question 2

Half-plane

Answer 2

A subset of a plane consisting of all points on a given side of a line in a plane. (2.3)

Question 3

Edge of a half-plane

Answer 3

The line that separates the plane into two half-planes. The line is not part of either half-plane. (2.3)

Question 4

Opposite half-planes

Answer 4

Are the two half-planes that are separated by a particular line of the plane (2.3)

Question 5

Angle

Answer 5

The union of two distinct rays with a common endpoint (2.3)

Question 6

Sides of an angle

Answer 6

The two rays that form the angle (2.3)

Question 7

Vertex of an angle

Answer 7

Is the common endpoint(origin) of the two rays (2.3)

Question 8

Interior of an angle

Answer 8

Inside of the vertex (2.3)

Question 9

Exterior of an angle

Answer 9

Outside of the vertex (2.3)

Question 10

A triangle

Question 11

Surface

Answer 11

A connected set of points in space having only the thickness of a point (2.6)

Question 12

Sphere

Answer 12

A surface in space consisting of the set of all points at a given distance from a given point (2.6)

Question 13

Center of a sphere

Answer 13

The given point (2.6)

Question 14

Radius of a sphere

Answer 14

A segment that connects a point of the sphere with the center (2.6)

Question 15

Closed surface

Answer 15

A surface with a finite size that divides other points in space into an interior and exterior (2.6)

Question 16

Solid

Answer 16

The union of a closed surface and its interior (2.6)

Question 17

Cone

Answer 17

The union of a region and all the segments that connect the boundary
of the region with a specific noncoplanar point (2.6)

Question 18

Cylinder

Answer 18

The union of the two regions of the same size and shape in different parallel planes, and the set of all segments that join corresponding points on the boundaries of the regions (2.6)

Question 19

Prism

Answer 19

A cylinder with polygonal regions as bases (2.6)

Question 20

Pyramid

Answer 20

A cone with a polygonal region as its base (2.6)

Question 21

Polyhedron

Answer 21

A closed surface made up of polygonal regions (2.7)

Question 22

Face of a polyhedron

Answer 22

One of the polygonal regions that form the surface of the polyhedron

Question 23

Regular polyhedron

Answer 23

A convex polyhedron having two properties

(1) . All faces are identical (same size and shape) and
(2) . The same number of edges meet at each vertex