Nancy has 3 groups of 10 and 7 left over

3 groups of ten is 30 and sven is seven so the answer is 37

“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 .