# 1_A Geometry Symbols for Web

```Details matter when naming
things in Geometry!
You must consider how the symbol is written:
 Capital letters / lowercase
 Print / cursive
 How many letters used
 Order of letters
 With an extra symbol or without
 Some things have more than one way to name them
Name
Point
Symbols Like…
One CAPITAL
print letter:
A
Simple Definition
A dot; a location on a
graph
Picture
Name
Line
Symbols
(2 methods!)
Simple
Definition
two capital letters with
double arrow on top:
A string of
points that
AB
line up and
continue
single lowercase
forever in
cursive letter
both
with nothing else:
directions
Picture
Name
line
segment
Symbols
the two
endpoints are
CAPITALIZED
with a bar on
top, in either
order:
AB
or
BA
Simple Definition
Part of a line, has two
endpoints
Picture
A
B
Name
Symbols
Simple Definition
Half of a line, has one
endpoint
ray
AB
Must be
written
first
Picture
Name
angle
Symbols
(3 methods!)
Simple Definition
With a number:
1
With three letters
(vertex in middle):
ABC or CBA
With the vertex only
(unless more than
one angle uses same
vertex): B
Picture
A
Two rays that have a
common endpoint
connecting them
B
C
vertex
Name
plane
Symbols
(2 methods!)
Simple
Definition
Picture
One CAPITAL CURSIVE
letter : M
Any three points in the
plane as long as they
are not on the same
line:
ABC
(order does not matter,
must be CAPITALIZED)
A flat surface
that extends
forever
A
B
C
M
OTHER SYMBOLS
The measure of a segment tells how long it is. It is shown by
removing the bar and just using the two letters: AB
The measure of an angle tells how many degrees it has. It is
shown by putting a small “m” in front of the angle’s name:
mABC
Congruent means two things have the same measure. It looks
like an equal sign with an extra squiggle on top:

Collinear points are points that lie on the same line.
Coplanar points are points that lie on the same plane.
- Share a common starting point and go in
opposite directions to form a line
intersection – where things meet or cross
Now work on
SYMBOL PRACTICE # 1
Geometry Symbols Practice # 1
Tell if each is a point, line, plane, line segment, ray, angle, measure of a line
segment, measure of an angle, or &quot;nothing&quot;. (Answers next page.)
1. location in space; no actual size
2. part of a line between two endpoints
3. &quot;half of a line&quot; extending in one direction forever
4. an infinite string of points; has no actual thickness
5. flat surface that extends indefinitely in all directions; no
actual thickness
Geometry Symbols Practice # 1
Tell if each is a point, line, plane, line segment, ray, angle, measure of a line
segment, measure of an angle, or &quot;nothing&quot;.
1. location in space; no actual size point
2. part of a line between two endpoints line segment
3. &quot;half of a line&quot; extending in one direction forever ray
4. an infinite string of points; has no actual thickness line
5. flat surface that extends indefinitely in all directions; no
actual thickness plane
Tell if each is a point, line, plane, line segment, ray, angle, measure of a line
segment, measure of an angle, or &quot;nothing&quot;. (Answers next page.)
6. one CAPITAL letter
cursive letter
8. single UPPERCASE Cursive letter
7. single lower-case,
9. two CAPITAL letters with → on top
10. three CAPITAL letters with no other symbol
11. two printed CAPITAL letters with ↔ on top
12. two CAPITAL letters with a — on top
Tell if each is a point, line, plane, line segment, ray, angle, measure of a line
segment, measure of an angle, or &quot;nothing&quot;.
6. one CAPITAL letter
point
cursive letter line
8. single UPPERCASE Cursive letter plane
7. single lower-case,
9. two CAPITAL letters with → on top
ray
10. three CAPITAL letters with no other symbol
plane
11. two printed CAPITAL letters with ↔ on top line
12. two CAPITAL letters with a — on top
segment
Tell if each is a point, line, plane, line segment, ray, angle, measure of a line
segment, measure of an angle, or &quot;nothing&quot;. (Answers next page.)
Tell if each is a point, line, plane, line segment, ray, angle, measure of a line
segment, measure of an angle, or &quot;nothing&quot;.
plane
line
point
angle
ray
segment
Measure of
an angle
angle
Tell if each is a point, line, plane, line segment, ray, angle, measure of a line
segment, measure of an angle, or &quot;nothing&quot;. (Answers next page.)
Tell if each is a point, line, plane, line segment, ray, angle, measure of a line
segment, measure of an angle, or &quot;nothing&quot;.
plane
segment
line
ray
line
point
NOTHING
plane
Arrow wrong way
Measure of a
segment
Measure
of an angle
line
segment
angle
NOTHING
No bar over planes
angle
Measure of an
angle
NOTHING
Planes capitalized
NOTHING
With arrow, lines
must be capitalized;
if cursive, use one
small letter and no
arrow