Suppose you know that ∠S and ∠Y are complementary, and that m∠S = 3(m∠Y) − 70°. Find m∠Y

The answer of the above is

“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 .