Judi solved the equation 1 - 18 = 43. Her work is shown.
What error did Judi make?

The anwser is 17 idk what she did but that’s wrong

“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 .