Great! Let's walk through this
real-life example step by step and verify the solution.
---
🔧 Problem Statement:
A 16-foot ladder is placed against a wall. According to a rule of thumb, the bottom of the ladder should be
one-fourth the length of the ladder away from the wall.
So:
- Length of ladder = 16 ft → so distance from wall = $ \frac{1}{4} \times 16 = 4 $ ft.
- We want to find how high up the wall the ladder reaches — that is, the
vertical height $ x $.
This forms a
right triangle, where:
- The ladder is the
hypotenuse ($ c = 16 $ ft),
- The base (distance from wall) is $ a = 4 $ ft,
- The height up the wall is $ b = x $ ft (unknown).
We use the
Pythagorean Theorem:
$$
a^2 + b^2 = c^2
$$
Substitute values:
$$
4^2 + x^2 = 16^2
$$
$$
16 + x^2 = 256
$$
Now subtract 16 from both sides:
$$
x^2 = 256 - 16 = 240
$$
Now take the square root:
$$
x = \sqrt{240}
$$
Let’s simplify:
$$
\sqrt{240} = \sqrt{16 \times 15} = 4\sqrt{15} \approx 4 \times 3.873 = 15.492
$$
So:
$$
x \approx 15.49 \text{ feet}
$$
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✔ Final Answer:
The ladder will reach approximately
15.49 feet up the wall.
> ✔️ Your handwritten work is
correct!
You wrote:
- $ x = \sqrt{240} $
- $ x \approx 15.49 $
And you correctly used the Pythagorean Theorem.
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📌 Summary:
-
Given: 16-ft ladder, 4 ft from wall
-
Find: Height on wall
-
Used: $ a^2 + b^2 = c^2 $
-
Result: $ x \approx 15.49 $ ft
✔ This is a practical application of right triangles in construction and safety!
Let me know if you'd like to explore what happens with different ladder lengths or angles!
Parent Tip: Review the logic above to help your child master the concept of real life pythagorean theorem examples.