Geometry Definitions 3-D figures

set of points in space a fixed distance (radius) from a certain point (center)

points of intersection b/w a plane & the center circle of a sphere

any circle on a plan that is not a great circle

given a region (base) & a point (vertex) not in the plane of the region, a conic solid is the set of points b/w the vertex & all points of the base, tog. w/ the vertex & base

surface of a conic solid whose base is a circle

surface of a conic solid whose base is a polygon

distance from the vertex to the nearest point of the base on that surface

always shorter than the edge of the lateral surface

distance from the vertex to the nearest point of the base on that surface

intersection of that figure w/ a plane

a view of the front, side, or back of a 3-D figure such as a house or building

a bird's eye view of a 3-D figure

2-D figure that can be folded into a 3-D figure

• given a line in a plane, there exists a point in the plane not in the line. Given a plane in space there exists a point in space not on the plane
• every line is a set of points that can be put into a one-to-one correspondence w/ the real #s, w/ any point on it corresponding to 0 & any other point corresponding to 1
• through any two points, there is exactly one line
• if two points lie in a plane, the line b/w them lies in the plane
• on a number line, there is a unique distance b/w two points
• through 3 non-collinear points (points that are not on the same line), there is exactly one plane.
• if 2 different planes have a point in common, then their intersection is a line

• a line (L) is perpendicular to a plane (X) if and only if it is perpendicular to every line in X through their intersection OR
• if the measureof an angle b/w a line and a plane is 90 degrees it is perpendicular to the plane

Yes. Every line oblique to a plane forms a right angle w/ exactly one line in the plane.

Undefined or indeterminable, the answer is a number that cannot be measured.