Geometry Symbols

Geometry Symbols – List of all geometry symbols and signs – meaning and examples.

Symbol	Symbol Name	Meaning / definition	Example
∠	angle	formed by two rays	∠ABC = 30°
	measured angle		ABC = 30°
	spherical angle		AOB = 30°
∟	right angle	= 90°	α = 90°
º	degree	1 turn = 360°	α = 60°
´	arcminute	1º = 60´	α = 60°59′
´´	arcsecond	1´ = 60´´	α = 60°59’59”
	line	infinite line
AB	line segment	line from point A to point B
	ray	line that start from point A
	arc	arc from point A to point B	= 60°
|	perpendicular	perpendicular lines (90° angle)	AC | BC
||	parallel	parallel lines	AB || CD
≅	congruent to	equivalence of geometric shapes and size	∆ABC ≅ ∆XYZ
~	similarity	same shapes, not same size	∆ABC ~ ∆XYZ
Δ	triangle	triangle shape	ΔABC ≅ ΔBCD
|x–y|	distance	distance between points x and y	| x–y | = 5
π	pi constant	π = 3.141592654… is the ratio between the circumference and diameter of a circle	c = π·d = 2·π·r
rad	radians	radians angle unit	360° = 2π rad
grad	grads	grads angle unit	360° = 400 grad