A ladder 13 m long leans against a vertical wall with its foot 5 m from the wall. How high up the wall does it reach?
Answer and explanation
Correct answer: A. 12 m
- Step 1: The ladder is the hypotenuse: 13^2 = 5^2 + h^2. Step 2. h^2 = 169 - 25 = 144, so h = 12 m. Answer: 12 m. Why not the others: 8 m: Subtracting the lengths ignores the right angle. 18 m: Adding the lengths ignores the right angle. 13 m: That is one more than the height the theorem gives.
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