1. **State the problem:** We need to find the distance between points A(1, 3) and B(9, 8) using Pythagoras' theorem. 2. **Identify the coordinates:** A(1, 3), B(9, 8). 3. **Calculate the differences in x and y:** $$\Delta x = 9 - 1 = 8$$ $$\Delta y = 8 - 3 = 5$$ 4. **Apply Pythagoras' theorem:** The distance $d$ is $$d = \sqrt{(\Delta x)^2 + (\Delta y)^2} = \sqrt{8^2 + 5^2} = \sqrt{64 + 25} = \sqrt{89}$$ 5. **Calculate the numeric value:** $$d \approx 9.433...$$ 6. **Round the answer to 1 decimal place:** $$d \approx 9.4$$ **Final answer:** The distance from A to B is 9.4 units.