Problem
\#9. A $4 \mathrm{~m}$ ladder leans against a building. If the bottom of the ladder is $1.3 \mathrm{~m}$ from the bottom of the building, how far up the wall will the ladder reach? Round your answer to one decimal place.
Solution
Step 1 ：Use the Pythagorean theorem: \(4^2 = 1.3^2 + x^2\)
Step 2 ：Solve for x: \(x = \sqrt{4^2 - 1.3^2} = 3.8\)
Step 3 ：\(\boxed{3.8}\) meters up the wall
