Help and explain pls :)

In the diagram, ab is tangent to c, ab = 4 inches, and ad = 2 inches. find the radius of the circle.

Ineed asap. 35 points. in order for two polygons to be similar, two conditions must be met. first, all pairs of corresponding sides must be in proportion. second, all corresponding angles must be congruent. prove that angle congruence is not enough, by itself, to establish that two polygons are similar. do this by describing or drawing two polygons that are not similar but whose corresponding angles are all congruent.

Pls i’m super dumb and i need with this one it’s due tomorrow