What are corresponding angles?
Angles that have the same relative position.
Explanation:
Whether they are in two triangles, or parallel lines, two angles that hold the same relative position are corresponding.
These are corresponding angles because they are formed by a transversal running through two parallel lines. They are also equal.
All three sets of angles in this diagram (green, pink, and blue) are corresponding angles because they belong to two similar triangles. These are also equal.
As a practice, try and find the corresponding angles in this diagram fig 3.
$$a$$ corresponds to $$g$$
$$b$$ corresponds to $$h$$
$$c$$ corresponds to $$e$$
$$d$$ corresponds to $$f$$