What is the perimeter and area of an equilateral triangle with a side measuring 6 ft?

A. Perimeter: 9 ft, Area: 24 ft²
B. Perimeter: 24 ft, Area: 15.6 ft²
C. Perimeter: 18 ft², Area: 15.6 ft²
D. Perimeter: 18 ft, Area: 15.6 ft²

E. None of the above answers are correct.



Answer :

To determine the perimeter and area of an equilateral triangle with each side measuring 6 feet, let's follow the steps involved.

### Step-by-Step Solution:

1. Perimeter Calculation:

The perimeter [tex]\( P \)[/tex] of an equilateral triangle is found by adding the lengths of all three sides. Since all sides are equal, the formula is:

[tex]\[ P = 3 \times \text{side length} \][/tex]

Given the side length is 6 feet:

[tex]\[ P = 3 \times 6 = 18 \text{ feet} \][/tex]

So, the perimeter of the equilateral triangle is 18 feet.

2. Area Calculation:

The area [tex]\( A \)[/tex] of an equilateral triangle can be calculated using the formula:

[tex]\[ A = \frac{\sqrt{3}}{4} \times \text{side length}^2 \][/tex]

Given the side length is 6 feet, we substitute into the formula:

[tex]\[ A = \frac{\sqrt{3}}{4} \times 6^2 \][/tex]

Calculating inside the parentheses first:

[tex]\[ 6^2 = 36 \][/tex]

Now multiply:

[tex]\[ A = \frac{\sqrt{3}}{4} \times 36 \][/tex]

The value of [tex]\( \sqrt{3} \)[/tex] approximately equals 1.732. So,

[tex]\[ A \approx \frac{1.732}{4} \times 36 \][/tex]

Simplify the fraction first:

[tex]\[ \frac{1.732}{4} = 0.433 \][/tex]

Now multiply by 36:

[tex]\[ A \approx 0.433 \times 36 = 15.588 \][/tex]

So, the area of the equilateral triangle is approximately 15.588 square feet.

### Conclusion:

Given the above calculations:
- The perimeter of the equilateral triangle is [tex]\( 18 \)[/tex] feet.
- The area of the equilateral triangle is approximately [tex]\( 15.6 \)[/tex] square feet.

The correct answer is:
- Perimeter [tex]\(= 18 \, \text{ft}\)[/tex]
- Area [tex]\(= 15.6 \, \text{ft}^2\)[/tex]