Construction

'P3'

'P2'

'P1'

'df1'

'df2'

'df1 + df2'

costr_1 = (0, 0)
F_1 = (-4, 0)
F_2 = (4, 0)
costr_2 = (0, 3)
ellipse = Ellipse(F_1, F_2, costr_2)
xAx = Line(F_1, F_2)
yAx = Line(costr_2, costr_1)
par = Line(costr_2, xAx)
a = OrthogonalLine(F_1, xAx)
b = OrthogonalLine(F_2, xAx)
P_1 = Point(ellipse)
P_2 = Point(yAx)
P_3 = Point(par)
df1_1 = Segment(F_1, P_1)
df2_1 = Segment(F_2, P_1)
df1_2 = Segment(F_1, P_2)
df2_2 = Segment(P_2, F_2)
df1_3 = Segment(F_1, P_3)
df2_3 = Segment(P_3, F_2)
viewConstr = false
B2: df1_1
B3: df1_2
B4: df1_3
C2: df2_1
C3: df2_2
C4: df2_3
D2: C2 + B2
D3: C3 + B3
D4: C4 + B4