In order to generalize, you might use a list and sort it:
import math
side = []
side.append(float(input()))
side.append(float(input()))
side.append(float(input()))
side.sort()
count = 0
if side[0]==side[1]:
count = count + 1
if side[1]==side[2]:
count = count + 1
if count == 2:
area = side[0]**2*math.sqrt(3)/4
print("equilateral, area = ", area)
elif count == 1:
distinct = side[0] if side[1]==side[2] else side[2]
print("isoscel, distinct side = ", distinct)
else:
print("scalene, max side = ", side[2])