def isLegalTriangle(s1: float, s2: float, s3: float) -> bool:
    """Return True if s1, s2, and s3 can form a legal triangle, False otherwise."""
    return s1 + s2 > s3 and s2 + s3 > s1 and s3 + s1 > s2


print("Testing isLegalTriangle()...", end="")
assert isLegalTriangle(8, 6, 7) == True
assert isLegalTriangle(3.0, 4.0, 5) == True
assert isLegalTriangle(4, 2, 3) == True
assert isLegalTriangle(2, 4, 3) == True
assert isLegalTriangle(2, 3, 5) == False
assert isLegalTriangle(0, 1, 2) == False
assert isLegalTriangle(-1, -2.0, -5) == False
assert isLegalTriangle(2, 2, 9) == False
print("Passed!")