select the relations that are functions.
{(a. 1), (b. 1), (0, 1)]
{(a, a), (a, b). (a, c)]
{(1, a), (2. a). (3.a)
{(a, a), (b, b), (c. c)]

This does not make sense

“exterior angles of triangles. an exterior (or external) angle is the angle between one side of a triangle and the extension of an adjacent side. try this drag the orange dots on any vertex to reshape the triangle.” look to get to the answer i explained what it means and other things i hope it you .