Triangles ABC and DEF are similar. Triangle DEF is an enlargement scale factor 2. Line segment EF corresponds to AC. EF = AC × 2. EF = 3 × 2. EF = 6 cm. Similarly, line segment DE corresponds to BC.

If two similar triangles have a scale factor 5:3 which statement regarding the two triangles is true? a) The ratio of their perimeters is 15:1. b) Their altitudes have a ratio 25:15.