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 .
