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° |
° | degree | 1 turn = 360° | α = 60° |
deg | degree | 1 turn = 360deg | α = 60deg |
′ | prime | arcminute, 1° = 60′ | α = 60°59′ |
″ | double prime | 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 |
c | radians | radians angle unit | 360° = 2π c |
grad | gradians / gons | grads angle unit | 360° = 400 grad |
g | gradians / gons | grads angle unit | 360° = 400 g |