You know that 3+3+3+3=4*3=12.this shows that 4 groups of 3 equal 12. the expression x +x+x+x+=4x means x is used as an addend 4 times. write an equivalent expression for m+m+m.

“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 .