Constant 
Denoted by 
Value 

Euler's number 
$e$ 
~2.71828 
Imaginary unit $i$ 
$i$ 
$\sqrt{1}$ 
Pythagoras' constant 
$\sqrt{2}$ 
~1.41421 
Archimedes' constant 
$π$ 
~3.14159 
$$ i^0 = 1$$ 
$$ i^1 = i$$ 
$$ i^2 = 1$$ 
$$ i^3 = i$$ 
$$ i^4 = 1$$ 
$$ i^5 = i$$ 
$$ i^6 = 1$$ 
$$ i^7 = i$$ 
$$ i^{1} = i$$ 
$$ i^{2} = 1$$ 
$$ i^{3} = i$$ 
$$ i^{4} = 1$$ 
$$ i^5 = i$$ 
$$ i^6 = 1$$ 
$$ i^7 = i$$ 
$$ i^8 = 1$$ 

The square root of 2 is equal to the length of the hypotenuse of a right triangle with sides of length 1 

$$π = \frac{C}{d} = \frac{C}{2r}$$ 