Hello!
To solve the first problem:
Radii are lines that go from the center of a circle to the edge. There are three of these lines in this circle.
The radii for this circle are lines AD, AC, and AD.
The correct answer choice is answer choice C.
To solve the second problem:
We have two congruent triangles. This means that their sides and angles are identical. We need to find the angles that are equal to that of angles A and C in triangle one.
These would be angles D and F.
The correct answer choice is answer choice A.
Hope this helps!