If the sides of a triangle are [tex]$56 \text{ cm}$[/tex], [tex]$65 \text{ cm}$[/tex], and [tex]$52 \text{ cm}$[/tex] long, then the area of the triangle is:

(a) [tex]$1322 \text{ cm}^2$[/tex]

(d) [tex]$100 \sqrt{3} \text{ m}$[/tex]



Answer :

To find the area of the triangle with sides of lengths 56 cm, 65 cm, and 52 cm, we can use Heron's formula. Here is the step-by-step process:

1. Determine the semi-perimeter (s):
The semi-perimeter of a triangle is half the perimeter of the triangle. It is calculated as:
[tex]\[ s = \frac{a + b + c}{2} \][/tex]
Given:
[tex]\[ a = 56 \, \text{cm}, \, b = 65 \, \text{cm}, \, c = 52 \, \text{cm} \][/tex]
Substituting these values in:
[tex]\[ s = \frac{56 + 65 + 52}{2} = \frac{173}{2} = 86.5 \, \text{cm} \][/tex]

2. Use Heron's formula to find the area (A):
Heron's formula for the area of a triangle is:
[tex]\[ A = \sqrt{s(s-a)(s-b)(s-c)} \][/tex]
Substituting [tex]\( s = 86.5 \, \text{cm} \)[/tex]:

[tex]\[ A = \sqrt{86.5 (86.5 - 56) (86.5 - 65) (86.5 - 52)} \][/tex]

Calculate the individual terms:
[tex]\[ s - a = 86.5 - 56 = 30.5 \][/tex]
[tex]\[ s - b = 86.5 - 65 = 21.5 \][/tex]
[tex]\[ s - c = 86.5 - 52 = 34.5 \][/tex]

Now plug these back into the formula:
[tex]\[ A = \sqrt{86.5 \times 30.5 \times 21.5 \times 34.5} \][/tex]

3. Calculate the product inside the square root:
[tex]\[ 86.5 \times 30.5 \times 21.5 \times 34.5 \approx 1,956,920.575 \][/tex]

4. Take the square root:
[tex]\[ A \approx \sqrt{1,956,920.575} \approx 1,398.9 \, \text{cm}^2 \][/tex]

Therefore, the area of the triangle is approximately:
[tex]\[ A \approx 1398.9 \, \text{cm}^2 \][/tex]