Answer:
The scale factor is 2.
Step-by-step explanation:
Take the vertical sides of the 2 triangles.
Their length is 3 and 6 so the scale factor is 6/3 = 2.
Also we see than the horizontal lines are in the same ratio 4 : 2 = 2:1.
4 pieces for the shelves
3/4×4=3
240cm
