import matplotlib.pyplot as plt

%matplotlib widget

fig, ax = plt.subplots()

circ = plt.Circle((5.0, 6.0), radius=2.4)

ax.add_artist(circ)

ax.set_xlim((0, 10))
ax.set_ylim((0, 10))

ax.set_aspect('equal')

circ.radius = 5.0