import math

def summa_3(a, b, c):
    return a + b + c

def summa_4(a, b, c, d):
    return a + b + c + d

def square(a, b, c):
    return a**2 + b**2 + c**2

def circle_diameter(radius):
    return radius * 2

def circle_area(radius):
    return math.pi * (radius ** 2)

def speed_finder(time, distance):
    return distance / time

def time_finder(speed, distance):
    return distance / speed

def distance_finder(speed, time):
    return speed * time
