C: circumference

D: the diameter of the circle

tall

length

O: the center of the circle and the origin of coordinates.

R: the radius of the circle

Student: Area

Five: volume

Σ σ` σ σ sum (in words), area density; Transconductance (lowercase)

α α α α α a: lf α angle; coefficient

Zetazat tower cutoff coefficient; Azimuth; Impedance; Relative viscosity; atomic number

The cardinal number of ε ε ε ε ε ε logarithm

υυu jup ` silon yupusilong displacement

χ χ Chi Phai West

∏πππππππππππππππππππππππππππππππππππππππππππππππππππππππππππ πππππππππππππππππππππππππππππππππππππππππππππππππππππππππ

τ τ τ τ Sets the time constant.

Ω Ω o`miga Ω ohm (in words); Angular velocity (lowercase); corner