Answer:
Vertical angles
Explanation:
Supplementary angles : A pair of angles whose sum is 180°,
Vertical angles : A pairs of opposite angles which are made by two intersecting lines.
Complementary angles : A pair of angles whose sum is 90°,
In the given diagram,
The measurements of ∠BOD and ∠COA are not given,
Thus, we can not say that they are supplementary or complementary,
But, ∠BOD and ∠COA are opposite angles formed in the intersection of lines AD and BD.
Hence, they are vertical angles.
Note : two figures are called similar if they have same shape however have different size. While, angles are not a figure.
Thus, they can not be similar. They can be equal or unequal.