Math Problem Statement

Please solve

Find the height of the triangular prism. An 8-meter length connects the triangular front and back of a house roof. The base of the front triangle measures 7.2 meters. Find the height of the roof’s front and back if the volume inside the roof is 144 cubic meters.

Solution

To solve the problem of finding the height of the triangular prism, let us break it down step by step:

Given:

  • The length of the prism is 8m8 \, \text{m}.
  • The base of the triangular face is 7.2m7.2 \, \text{m}.
  • The volume of the prism is 144m3144 \, \text{m}^3.
  • We are solving for the height of the triangular face.

Formula for the Volume of a Triangular Prism:

The volume VV of a triangular prism is calculated as: V=Base Area of the Triangle×Length of the PrismV = \text{Base Area of the Triangle} \times \text{Length of the Prism}

The area of the triangular face is: Base Area of the Triangle=12×Base of the Triangle×Height of the Triangle\text{Base Area of the Triangle} = \frac{1}{2} \times \text{Base of the Triangle} \times \text{Height of the Triangle}

Substitute this into the volume formula: V=12×Base of the Triangle×Height of the Triangle×Length of the PrismV = \frac{1}{2} \times \text{Base of the Triangle} \times \text{Height of the Triangle} \times \text{Length of the Prism}


Substituting the Known Values:

We are given:

  • V=144m3V = 144 \, \text{m}^3
  • Base of the triangle = 7.2m7.2 \, \text{m}
  • Length of the prism = 8m8 \, \text{m}

Substitute into the formula: 144=12×7.2×h×8144 = \frac{1}{2} \times 7.2 \times h \times 8

Simplify step by step:

  1. 12×7.2=3.6\frac{1}{2} \times 7.2 = 3.6
  2. 3.6×8=28.83.6 \times 8 = 28.8

So: 144=28.8×h144 = 28.8 \times h

Solve for hh: h=14428.8=5mh = \frac{144}{28.8} = 5 \, \text{m}


Final Answer:

The height of the triangular prism is: 5m\boxed{5 \, \text{m}}

This matches the second option provided.


Do you need further details or clarifications?


Related Questions:

  1. How is the formula for the volume of a triangular prism derived?
  2. If the height of the triangle were doubled, what would the volume be?
  3. What happens to the volume if the base of the triangular face is halved?
  4. Can the same formula be used for other shapes of prisms? Why or why not?
  5. What units are used to measure volume, and how do they differ from area or length?

Tip:

Always double-check whether the units are consistent across the problem (e.g., meters for length, cubic meters for volume) to avoid mistakes.

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Math Problem Analysis

Mathematical Concepts

Geometry
Volume of Prisms

Formulas

Volume of a triangular prism = (1/2) × base × height × length

Theorems

Basic geometry theorem for prism volumes

Suitable Grade Level

Grades 6-8