If A (9 18) and B (1 12) what is the length of?

To find the length between points A (9, 18) and B (1, 12), we can use the distance formula: ( d = \sqrt{(x_2 - x_1)^2 + (y_2 - y_1)^2} ). Plugging in the coordinates gives us ( d = \sqrt{(1 - 9)^2 + (12 - 18)^2} = \sqrt{(-8)^2 + (-6)^2} = \sqrt{64 + 36} = \sqrt{100} = 10 ). Thus, the length between points A and B is 10 units.