Math Problem Statement

MAKE SURE YOU ARE SHOWING WORK.

You are building a flower bed. It is going to be triangular.

You want to know how much topsoil to get, so you need to figure out the area of the triangle.

You measure all three sides and find them to be: a = 5ft, b = 7ft, and c = 8ft.

Draw out a triangle and label it.

What is the area of the triangle? (make sure to include units).

Solution

To solve for the area of the triangle, we can use Heron's Formula. This formula calculates the area of a triangle when all three sides are known.

Step-by-Step Solution:

  1. Label the Triangle
    First, let's draw and label the triangle with sides a=5a = 5 feet, b=7b = 7 feet, and c=8c = 8 feet.

           c = 8 ft
        A___________C
        |          /
        |        /
      a=5ft    /
        |    /
        |  /
        |/
       B
        b=7ft
    
  2. Calculate the Semi-Perimeter ss
    The semi-perimeter ss is half of the triangle's perimeter: s=a+b+c2s = \frac{a + b + c}{2} Substituting the values: s=5+7+82=202=10 fts = \frac{5 + 7 + 8}{2} = \frac{20}{2} = 10 \text{ ft}

  3. Apply Heron's Formula
    Heron's formula for the area AA of a triangle is: A=s(sa)(sb)(sc)A = \sqrt{s(s - a)(s - b)(s - c)} Substituting the values of ss, aa, bb, and cc: A=10(105)(107)(108)A = \sqrt{10(10 - 5)(10 - 7)(10 - 8)} Simplify inside the parentheses: A=10×5×3×2A = \sqrt{10 \times 5 \times 3 \times 2} Continue calculating: A=10×5×3×2=300A = \sqrt{10 \times 5 \times 3 \times 2} = \sqrt{300} Taking the square root: A17.32 square feetA \approx 17.32 \text{ square feet}

Final Answer:

The area of the triangle is approximately 17.32 square feet.


Would you like additional details on any of these steps?

Here are five related questions to explore further:

  1. How would the area change if side lengths were different?
  2. What other methods can we use to find the area of a triangle?
  3. How can we use trigonometry to verify the area of this triangle?
  4. What is the importance of knowing the triangle's semi-perimeter?
  5. How would you calculate the perimeter of the triangle?

Tip: Heron’s formula is most useful when you know all three sides but no angles of a triangle.

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Math Problem Analysis

Mathematical Concepts

Geometry
Triangle Area Calculation
Heron's Formula

Formulas

Heron's formula for the area of a triangle, A = sqrt(s(s - a)(s - b)(s - c))
Semi-perimeter calculation, s = (a + b + c) / 2

Theorems

Heron's Theorem

Suitable Grade Level

Grades 8-10