Computing the area of a convex hull in scipy

I wanted to compute the convex hull for a couple of points on a plane, using scipy.

Here is my code:

import numpy as np
from scipy.spatial import ConvexHull

points = np.array([[10, 10], [30, 10], [30, 20], [10, 20]])
hull = ConvexHull(points)
print(hull.vertices, hull.area)

It prints: [0 1 2 3] 60.0

So, the perimeter rather than area is returned (I checked another example, same behavior). Is this a bug? Python 3.7.4 (64-bit), scipy 1.3.1.