Answer:
3
Step-by-step explanation:
The gray triangle is 2 units tall, and 3 units long. Using the equation 3*2, we can find the area of the square. (Base * height = area) {PS: that only works on rectangles/squares} With that, we get that it is 6 square units in area. From here, we do the same with the large rectangle. It is 6 units tall, and 9 units long. Doing the calculations: 9*6 = 54 square units area.
With that, we can test to make sure the scale factor is 3 by multiplying all the side lengths by 3 and seeing if they line up with the larger rectangle.
3*2 = 6, and 3*3 = 9. So the scale factor is 3
