Geometry Cheat Sheet

Geometry Symbols

AA	Angle-angle, for proving triangles similar
AAS	Angle-angle-side, for proving triangles congruent
ASA	Angle-side-angle, for proving triangles congruent
cos	Cosine
cot	Cotangent
CPCTC	Congruent parts of congruent triangles are congruent
csc	Cosecant
CSSTP	Corresponding sides of similar triangles are proportional
SAS	Side-angle-side, for proving triangles congruent
sin	Sine
tan	Tangent

a	Apothem
a, b, c	Lengths of the sides of a triangle
A	Area of a polygon
B	Area of the base of a solid
C	Circumference of a circle
h	Height of an altitude
α	Alpha (name of an angle)
β	Beta (name of an angle)
X1 ^x	Unknown value
θ	Theta (name of an angle)
π	Pi
	Slant length of a side of a solid
l or l	Length of a rectangle
L	Lateral area of a solid
m	Slope of a line
M	Midpoint of a line segment
n	Number of sides of a polygon
P	Perimeter of a polygon
P or P'	Plane
r	Radius
s	Length of the side of an equilateral polygon
S	Surface area of a solid
T	Total area
V	Volume
w or w	Width of a rectangle

Area	(A) of a triangle A = ½bh where b measures the base and h the altitude
Perimeter	(P) of a triangle P = a + b + c where a, b, and c are the lengths of the sides
Area	(A) of a rectangle A = lw where l measures the length and w the width
Perimeter	(P) of a rectangle P = 2b + 2h where b measures the width and h the height
Area	(A) of a circle A = πr² where r measures the radius
Area	Circumference (C) of a circle C = 2πr or C = πd where r measures the radius and d the diameter