any number larger than 1 or less than -1 will result enlargment (with center at (0,0) so answers are: 10: enlargement 11: 2/5 = 0.4 reduction 12: redusction 13: 1 isometric 14: enlargment 15: reduction 16: scale is 1.5 17: scale is 0.5 18: scale is 0.5 19 triangles are not scaled. ther are different .