A triangle with vertices at A(0, 0), B(0, 4), and C(6, 0) is dilated to yield a triangle with vertices at A′(0, 0), B′(0, 10), and C′(15, 0). What is the scale factor of the dilation?

Answer 1

At first the length of AB is 4 and after the transformation the length of A'B' is 10. Therefore the dilation scale factor is 10/4=2.5

The same thing applies to the length of AC, which starts at 6 and goes up to 15. 15/6 = 2.5