Answer:
5
Explanation:
The first step in finding the scale factor is seeing if the shape is enlarged or reduced in size, it says for your problem that the shale is enlarged. Now you need to match the sides to the numbers. The enlarged rectangles lenght is 20, the starting one is 5, thats really all we need. We can say that we are enlarging 5 to 20, and to do this we need to multiply by 4. To check your answer,use the other numbers, the width normal is 2.5 and the width enlarged is 10, so we can say we are enlarging 2.5 to 10, and to do that we also need 5, so 5 is the correct number in which the shape is being enlarged or also know as the scale factor