Unit 1: Introduction to Geometry – Fill-in-the-Blank Flashcards

30 fill-in-the-blank flashcards covering key vocabulary, properties, and concepts from Unit 1: Introduction to Geometry.

Points that lie on the same line are called __.

collinear

Lines that intersect at a single point are described as __.

concurrent

Figures that lie on the same plane are __.

coplanar

An angle measuring less than 90° is called an __ angle.

acute

An angle measuring exactly 90° is called a __ angle.

right

An angle measuring more than 90° is called an __ angle.

obtuse

A polygon with 3 sides is called a __.

triangle

A polygon with 4 sides is called a __.

quadrilateral

A polygon with 5 sides is called a __.

pentagon

A polygon with 6 sides is called a __.

hexagon

A polygon with 7 sides is called a __.

heptagon

A polygon with 8 sides is called an __.

octagon

A polygon with 9 sides is called a __.

nonagon

A polygon with 10 sides is called a __.

decagon

Lines in the same plane that never intersect are called __ lines.

parallel

Lines that intersect to form right angles are called __ lines.

perpendicular

A __ extends endlessly in two opposite directions.

line

A __ has one endpoint and extends endlessly in one direction.

ray

A __ has two endpoints and is the part of a line between them.

line segment

The intersection of two lines is always a __.

point

A __ is a flat surface that extends without end in all directions.

plane

Points that are not on the same line are described as __.

noncollinear

A line is __-dimensional.

one

Parallel lines intersect in __ points.

zero

Any three noncollinear points determine a __.

plane

In a regular hexagon ABCDEF, lines ED and DC are __ at point D.

concurrent

A rectangle is bounded on its edges, whereas a __ is unbounded.

plane

A line has no __, while a line segment does.

endpoints

A ray extends forever in __ direction(s).

one

A square pyramid has four __ as its lateral faces.

triangles