Answer:
When you join points D(2,3),O(0,0)and E(5,1) which are not collinear it will form a triangle.
Now , Adjacent of ∠ DOE are [ ∠ ODE and ∠OED] .
As we know that Sum of three interior angles of a triangle is 180°.
∠ DOE + ∠OED+∠EDO = 180°
∠DOE=180°- (∠OED+∠EDO)
Supplementary ,of ∠DOE is (∠OED+∠EDO).