A ladder 25 m long leans against a vertical wall with its foot 7 m from the wall. How high up the wall does it reach?
Answer and explanation
Correct answer: A. 24 m
- Step 1: The ladder is the hypotenuse: 25^2 = 7^2 + h^2. Step 2. h^2 = 625 - 49 = 576, so h = 24 m. Answer: 24 m. Why not the others: 18 m: Subtracting the lengths ignores the right angle. 32 m: Adding the lengths ignores the right angle. 25 m: That is one more than the height the theorem gives.
Practise more Pythagoras theorem.
Free questions with an explanation for every one, and full timed Kenya KCSE mock tests.
More Pythagoras theorem questions
- A ladder 5 m long leans against a vertical wall with its foot 3 m from the wall. How high up the wall does it reach?
- 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?
- A ladder 17 m long leans against a vertical wall with its foot 8 m from the wall. How high up the wall does it reach?
- A ladder 29 m long leans against a vertical wall with its foot 20 m from the wall. How high up the wall does it reach?
- A ladder 41 m long leans against a vertical wall with its foot 9 m from the wall. How high up the wall does it reach?