import matplotlib.pyplot as plt
import numpy as np
from matplotlib.patches import Polygon

y = np.array([[1,1],[2,3],[3,1]])
p = Polygon(y,facecolor='m',alpha=.5)

y1 = np.array([[2,2],[2.5,4],[3.5,1]])
p1 = Polygon(y1,facecolor='b',alpha=.5,edgecolor='k')

fig,ax = plt.subplots()

ax.add_patch(p)
ax.add_patch(p1)

ax.set_ylim([0,4])
ax.set_xlim([0,4])
plt.show()

x = np.linspace(-2,2,101)
f = -x**2

pnts = np.vstack((x,f)).T
print(np.shape(pnts))
print(pnts)

(101, 2)
[[-2.0000e+00 -4.0000e+00]
 [-1.9600e+00 -3.8416e+00]
 [-1.9200e+00 -3.6864e+00]
 [-1.8800e+00 -3.5344e+00]
 [-1.8400e+00 -3.3856e+00]
 [-1.8000e+00 -3.2400e+00]
 [-1.7600e+00 -3.0976e+00]
 [-1.7200e+00 -2.9584e+00]
 [-1.6800e+00 -2.8224e+00]
 [-1.6400e+00 -2.6896e+00]
 [-1.6000e+00 -2.5600e+00]
 [-1.5600e+00 -2.4336e+00]
 [-1.5200e+00 -2.3104e+00]
 [-1.4800e+00 -2.1904e+00]
 [-1.4400e+00 -2.0736e+00]
 [-1.4000e+00 -1.9600e+00]
 [-1.3600e+00 -1.8496e+00]
 [-1.3200e+00 -1.7424e+00]
 [-1.2800e+00 -1.6384e+00]
 [-1.2400e+00 -1.5376e+00]
 [-1.2000e+00 -1.4400e+00]
 [-1.1600e+00 -1.3456e+00]
 [-1.1200e+00 -1.2544e+00]
 [-1.0800e+00 -1.1664e+00]
 [-1.0400e+00 -1.0816e+00]
 [-1.0000e+00 -1.0000e+00]
 [-9.6000e-01 -9.2160e-01]
 [-9.2000e-01 -8.4640e-01]
 [-8.8000e-01 -7.7440e-01]
 [-8.4000e-01 -7.0560e-01]
 [-8.0000e-01 -6.4000e-01]
 [-7.6000e-01 -5.7760e-01]
 [-7.2000e-01 -5.1840e-01]
 [-6.8000e-01 -4.6240e-01]
 [-6.4000e-01 -4.0960e-01]
 [-6.0000e-01 -3.6000e-01]
 [-5.6000e-01 -3.1360e-01]
 [-5.2000e-01 -2.7040e-01]
 [-4.8000e-01 -2.3040e-01]
 [-4.4000e-01 -1.9360e-01]
 [-4.0000e-01 -1.6000e-01]
 [-3.6000e-01 -1.2960e-01]
 [-3.2000e-01 -1.0240e-01]
 [-2.8000e-01 -7.8400e-02]
 [-2.4000e-01 -5.7600e-02]
 [-2.0000e-01 -4.0000e-02]
 [-1.6000e-01 -2.5600e-02]
 [-1.2000e-01 -1.4400e-02]
 [-8.0000e-02 -6.4000e-03]
 [-4.0000e-02 -1.6000e-03]
 [ 0.0000e+00 -0.0000e+00]
 [ 4.0000e-02 -1.6000e-03]
 [ 8.0000e-02 -6.4000e-03]
 [ 1.2000e-01 -1.4400e-02]
 [ 1.6000e-01 -2.5600e-02]
 [ 2.0000e-01 -4.0000e-02]
 [ 2.4000e-01 -5.7600e-02]
 [ 2.8000e-01 -7.8400e-02]
 [ 3.2000e-01 -1.0240e-01]
 [ 3.6000e-01 -1.2960e-01]
 [ 4.0000e-01 -1.6000e-01]
 [ 4.4000e-01 -1.9360e-01]
 [ 4.8000e-01 -2.3040e-01]
 [ 5.2000e-01 -2.7040e-01]
 [ 5.6000e-01 -3.1360e-01]
 [ 6.0000e-01 -3.6000e-01]
 [ 6.4000e-01 -4.0960e-01]
 [ 6.8000e-01 -4.6240e-01]
 [ 7.2000e-01 -5.1840e-01]
 [ 7.6000e-01 -5.7760e-01]
 [ 8.0000e-01 -6.4000e-01]
 [ 8.4000e-01 -7.0560e-01]
 [ 8.8000e-01 -7.7440e-01]
 [ 9.2000e-01 -8.4640e-01]
 [ 9.6000e-01 -9.2160e-01]
 [ 1.0000e+00 -1.0000e+00]
 [ 1.0400e+00 -1.0816e+00]
 [ 1.0800e+00 -1.1664e+00]
 [ 1.1200e+00 -1.2544e+00]
 [ 1.1600e+00 -1.3456e+00]
 [ 1.2000e+00 -1.4400e+00]
 [ 1.2400e+00 -1.5376e+00]
 [ 1.2800e+00 -1.6384e+00]
 [ 1.3200e+00 -1.7424e+00]
 [ 1.3600e+00 -1.8496e+00]
 [ 1.4000e+00 -1.9600e+00]
 [ 1.4400e+00 -2.0736e+00]
 [ 1.4800e+00 -2.1904e+00]
 [ 1.5200e+00 -2.3104e+00]
 [ 1.5600e+00 -2.4336e+00]
 [ 1.6000e+00 -2.5600e+00]
 [ 1.6400e+00 -2.6896e+00]
 [ 1.6800e+00 -2.8224e+00]
 [ 1.7200e+00 -2.9584e+00]
 [ 1.7600e+00 -3.0976e+00]
 [ 1.8000e+00 -3.2400e+00]
 [ 1.8400e+00 -3.3856e+00]
 [ 1.8800e+00 -3.5344e+00]
 [ 1.9200e+00 -3.6864e+00]
 [ 1.9600e+00 -3.8416e+00]
 [ 2.0000e+00 -4.0000e+00]]

p = Polygon(pnts, facecolor='g', alpha = .5, edgecolor='k')

y = np.array([[-.5,-4],[-.5,-2.5],[.5,-2.5],[.5,-4]])
p1 = Polygon(y, facecolor='k', alpha = 1, edgecolor='k')

fig,ax = plt.subplots()
ax.add_patch(p)
ax.add_patch(p1)

plt.plot(x,f,'k')
plt.plot([-2,2],[-4,-4],'k')
plt.axis('off')

plt.savefig('figure.png')
plt.savefig('figure.pdf')

plt.show()