Math Problem Statement

Dans la maison de René, la base du toit mesure 9 m et les versants du toit mesurent 5,6 m comme indiqué sur le dessin. Calculer la hauteur SH du grenier.

Solution

The exercise is asking to calculate the height SHSH of the attic (grenier) in René's house, based on the geometric properties of the roof. Here's how to solve the problem step-by-step:


1. Understanding the Problem

The roof is in the shape of an isosceles triangle:

  • Base AB=9mAB = 9 \, \text{m},
  • Both slanted sides ASAS and SBSB measure 5.6m5.6 \, \text{m},
  • SHSH is the vertical height of the triangle, which splits ABAB into two equal halves at point HH.

This forms two right triangles SHA\triangle SHA and SHB\triangle SHB.


2. Using the Pythagorean Theorem

In one of the right triangles (e.g., SHA\triangle SHA):

  • Hypotenuse AS=5.6mAS = 5.6 \, \text{m},
  • Half of the base AH=AB2=92=4.5mAH = \frac{AB}{2} = \frac{9}{2} = 4.5 \, \text{m},
  • Height SHSH is the unknown we need to calculate.

Using the Pythagorean theorem: AS2=AH2+SH2AS^2 = AH^2 + SH^2 Substituting the known values: 5.62=4.52+SH25.6^2 = 4.5^2 + SH^2


3. Solving for SHSH

First, calculate 5.625.6^2 and 4.524.5^2: 5.62=31.36,4.52=20.255.6^2 = 31.36, \quad 4.5^2 = 20.25

Substitute these values into the equation: 31.36=20.25+SH231.36 = 20.25 + SH^2

Simplify to find SH2SH^2: SH2=31.3620.25=11.11SH^2 = 31.36 - 20.25 = 11.11

Take the square root of both sides: SH=11.113.33mSH = \sqrt{11.11} \approx 3.33 \, \text{m}


4. Final Answer

The height SHSH of the attic is approximately: 3.33m\boxed{3.33 \, \text{m}}


Would you like further clarification or details? Here are five related questions to deepen your understanding:

  1. How does the Pythagorean theorem apply to other roof designs or structures?
  2. What are the implications of changing the base length ABAB or the side lengths ASAS?
  3. How would the solution differ if ABAB were not split evenly by SHSH?
  4. Can you calculate the angle SAH\angle SAH using trigonometric functions?
  5. What are other practical uses of calculating heights in similar geometric problems?

Tip: Always double-check your calculations, especially when squaring or taking square roots, as small errors can lead to incorrect results!

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Math Problem Analysis

Mathematical Concepts

Geometry
Right Triangles
Pythagorean Theorem

Formulas

c^2 = a^2 + b^2 (Pythagorean theorem)

Theorems

Pythagorean Theorem

Suitable Grade Level

Grades 7-9